src/jdk.compiler/share/classes/com/sun/tools/javac/main/JavaCompiler.java
changeset 47216 71c04702a3d5
parent 45910 c7092e4591b2
child 48054 702043a4cdeb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/main/JavaCompiler.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1844 @@
+/*
+ * Copyright (c) 1999, 2017, 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.javac.main;
+
+import java.io.*;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.Map;
+import java.util.MissingResourceException;
+import java.util.Queue;
+import java.util.ResourceBundle;
+import java.util.Set;
+import java.util.function.Function;
+
+import javax.annotation.processing.Processor;
+import javax.lang.model.SourceVersion;
+import javax.lang.model.element.ElementVisitor;
+import javax.tools.DiagnosticListener;
+import javax.tools.JavaFileManager;
+import javax.tools.JavaFileObject;
+import javax.tools.JavaFileObject.Kind;
+import javax.tools.StandardLocation;
+
+import com.sun.source.util.TaskEvent;
+import com.sun.tools.javac.api.MultiTaskListener;
+import com.sun.tools.javac.code.*;
+import com.sun.tools.javac.code.Lint.LintCategory;
+import com.sun.tools.javac.code.Symbol.ClassSymbol;
+import com.sun.tools.javac.code.Symbol.CompletionFailure;
+import com.sun.tools.javac.code.Symbol.PackageSymbol;
+import com.sun.tools.javac.comp.*;
+import com.sun.tools.javac.comp.CompileStates.CompileState;
+import com.sun.tools.javac.file.JavacFileManager;
+import com.sun.tools.javac.jvm.*;
+import com.sun.tools.javac.parser.*;
+import com.sun.tools.javac.platform.PlatformDescription;
+import com.sun.tools.javac.processing.*;
+import com.sun.tools.javac.tree.*;
+import com.sun.tools.javac.tree.JCTree.JCClassDecl;
+import com.sun.tools.javac.tree.JCTree.JCCompilationUnit;
+import com.sun.tools.javac.tree.JCTree.JCExpression;
+import com.sun.tools.javac.tree.JCTree.JCLambda;
+import com.sun.tools.javac.tree.JCTree.JCMemberReference;
+import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
+import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
+import com.sun.tools.javac.util.*;
+import com.sun.tools.javac.util.DefinedBy.Api;
+import com.sun.tools.javac.util.JCDiagnostic.Factory;
+import com.sun.tools.javac.util.Log.DiagnosticHandler;
+import com.sun.tools.javac.util.Log.DiscardDiagnosticHandler;
+import com.sun.tools.javac.util.Log.WriterKind;
+
+import static com.sun.tools.javac.code.Kinds.Kind.*;
+
+import com.sun.tools.javac.code.Symbol.ModuleSymbol;
+import com.sun.tools.javac.resources.CompilerProperties.Errors;
+import com.sun.tools.javac.resources.CompilerProperties.Fragments;
+import com.sun.tools.javac.resources.CompilerProperties.Notes;
+import com.sun.tools.javac.resources.CompilerProperties.Warnings;
+
+import static com.sun.tools.javac.code.TypeTag.CLASS;
+import static com.sun.tools.javac.main.Option.*;
+import static com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag.*;
+
+import static javax.tools.StandardLocation.CLASS_OUTPUT;
+
+import com.sun.tools.javac.tree.JCTree.JCModuleDecl;
+
+/** This class could be the main entry point for GJC when GJC is used as a
+ *  component in a larger software system. It provides operations to
+ *  construct a new compiler, and to run a new compiler on a set of source
+ *  files.
+ *
+ *  <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 JavaCompiler {
+    /** The context key for the compiler. */
+    public static final Context.Key<JavaCompiler> compilerKey = new Context.Key<>();
+
+    /** Get the JavaCompiler instance for this context. */
+    public static JavaCompiler instance(Context context) {
+        JavaCompiler instance = context.get(compilerKey);
+        if (instance == null)
+            instance = new JavaCompiler(context);
+        return instance;
+    }
+
+    /** The current version number as a string.
+     */
+    public static String version() {
+        return version("release");  // mm.nn.oo[-milestone]
+    }
+
+    /** The current full version number as a string.
+     */
+    public static String fullVersion() {
+        return version("full"); // mm.mm.oo[-milestone]-build
+    }
+
+    private static final String versionRBName = "com.sun.tools.javac.resources.version";
+    private static ResourceBundle versionRB;
+
+    private static String version(String key) {
+        if (versionRB == null) {
+            try {
+                versionRB = ResourceBundle.getBundle(versionRBName);
+            } catch (MissingResourceException e) {
+                return Log.getLocalizedString("version.not.available");
+            }
+        }
+        try {
+            return versionRB.getString(key);
+        }
+        catch (MissingResourceException e) {
+            return Log.getLocalizedString("version.not.available");
+        }
+    }
+
+    /**
+     * Control how the compiler's latter phases (attr, flow, desugar, generate)
+     * are connected. Each individual file is processed by each phase in turn,
+     * but with different compile policies, you can control the order in which
+     * each class is processed through its next phase.
+     *
+     * <p>Generally speaking, the compiler will "fail fast" in the face of
+     * errors, although not aggressively so. flow, desugar, etc become no-ops
+     * once any errors have occurred. No attempt is currently made to determine
+     * if it might be safe to process a class through its next phase because
+     * it does not depend on any unrelated errors that might have occurred.
+     */
+    protected static enum CompilePolicy {
+        /**
+         * Just attribute the parse trees.
+         */
+        ATTR_ONLY,
+
+        /**
+         * Just attribute and do flow analysis on the parse trees.
+         * This should catch most user errors.
+         */
+        CHECK_ONLY,
+
+        /**
+         * Attribute everything, then do flow analysis for everything,
+         * then desugar everything, and only then generate output.
+         * This means no output will be generated if there are any
+         * errors in any classes.
+         */
+        SIMPLE,
+
+        /**
+         * Groups the classes for each source file together, then process
+         * each group in a manner equivalent to the {@code SIMPLE} policy.
+         * This means no output will be generated if there are any
+         * errors in any of the classes in a source file.
+         */
+        BY_FILE,
+
+        /**
+         * Completely process each entry on the todo list in turn.
+         * -- this is the same for 1.5.
+         * Means output might be generated for some classes in a compilation unit
+         * and not others.
+         */
+        BY_TODO;
+
+        static CompilePolicy decode(String option) {
+            if (option == null)
+                return DEFAULT_COMPILE_POLICY;
+            else if (option.equals("attr"))
+                return ATTR_ONLY;
+            else if (option.equals("check"))
+                return CHECK_ONLY;
+            else if (option.equals("simple"))
+                return SIMPLE;
+            else if (option.equals("byfile"))
+                return BY_FILE;
+            else if (option.equals("bytodo"))
+                return BY_TODO;
+            else
+                return DEFAULT_COMPILE_POLICY;
+        }
+    }
+
+    private static final CompilePolicy DEFAULT_COMPILE_POLICY = CompilePolicy.BY_TODO;
+
+    protected static enum ImplicitSourcePolicy {
+        /** Don't generate or process implicitly read source files. */
+        NONE,
+        /** Generate classes for implicitly read source files. */
+        CLASS,
+        /** Like CLASS, but generate warnings if annotation processing occurs */
+        UNSET;
+
+        static ImplicitSourcePolicy decode(String option) {
+            if (option == null)
+                return UNSET;
+            else if (option.equals("none"))
+                return NONE;
+            else if (option.equals("class"))
+                return CLASS;
+            else
+                return UNSET;
+        }
+    }
+
+    /** The log to be used for error reporting.
+     */
+    public Log log;
+
+    /** Factory for creating diagnostic objects
+     */
+    JCDiagnostic.Factory diagFactory;
+
+    /** The tree factory module.
+     */
+    protected TreeMaker make;
+
+    /** The class finder.
+     */
+    protected ClassFinder finder;
+
+    /** The class reader.
+     */
+    protected ClassReader reader;
+
+    /** The class writer.
+     */
+    protected ClassWriter writer;
+
+    /** The native header writer.
+     */
+    protected JNIWriter jniWriter;
+
+    /** The module for the symbol table entry phases.
+     */
+    protected Enter enter;
+
+    /** The symbol table.
+     */
+    protected Symtab syms;
+
+    /** The language version.
+     */
+    protected Source source;
+
+    /** The module for code generation.
+     */
+    protected Gen gen;
+
+    /** The name table.
+     */
+    protected Names names;
+
+    /** The attributor.
+     */
+    protected Attr attr;
+
+    /** The analyzer
+     */
+    protected Analyzer analyzer;
+
+    /** The attributor.
+     */
+    protected Check chk;
+
+    /** The flow analyzer.
+     */
+    protected Flow flow;
+
+    /** The modules visitor
+     */
+    protected Modules modules;
+
+    /** The module finder
+     */
+    protected ModuleFinder moduleFinder;
+
+    /** The diagnostics factory
+     */
+    protected JCDiagnostic.Factory diags;
+
+    /** The type eraser.
+     */
+    protected TransTypes transTypes;
+
+    /** The syntactic sugar desweetener.
+     */
+    protected Lower lower;
+
+    /** The annotation annotator.
+     */
+    protected Annotate annotate;
+
+    /** Force a completion failure on this name
+     */
+    protected final Name completionFailureName;
+
+    /** Type utilities.
+     */
+    protected Types types;
+
+    /** Access to file objects.
+     */
+    protected JavaFileManager fileManager;
+
+    /** Factory for parsers.
+     */
+    protected ParserFactory parserFactory;
+
+    /** Broadcasting listener for progress events
+     */
+    protected MultiTaskListener taskListener;
+
+    /**
+     * SourceCompleter that delegates to the readSourceFile method of this class.
+     */
+    protected final Symbol.Completer sourceCompleter =
+            sym -> readSourceFile((ClassSymbol) sym);
+
+    /**
+     * Command line options.
+     */
+    protected Options options;
+
+    protected Context context;
+
+    /**
+     * Flag set if any annotation processing occurred.
+     **/
+    protected boolean annotationProcessingOccurred;
+
+    /**
+     * Flag set if any implicit source files read.
+     **/
+    protected boolean implicitSourceFilesRead;
+
+    private boolean enterDone;
+
+    protected CompileStates compileStates;
+
+    /** Construct a new compiler using a shared context.
+     */
+    public JavaCompiler(Context context) {
+        this.context = context;
+        context.put(compilerKey, this);
+
+        // if fileManager not already set, register the JavacFileManager to be used
+        if (context.get(JavaFileManager.class) == null)
+            JavacFileManager.preRegister(context);
+
+        names = Names.instance(context);
+        log = Log.instance(context);
+        diagFactory = JCDiagnostic.Factory.instance(context);
+        finder = ClassFinder.instance(context);
+        reader = ClassReader.instance(context);
+        make = TreeMaker.instance(context);
+        writer = ClassWriter.instance(context);
+        jniWriter = JNIWriter.instance(context);
+        enter = Enter.instance(context);
+        todo = Todo.instance(context);
+
+        fileManager = context.get(JavaFileManager.class);
+        parserFactory = ParserFactory.instance(context);
+        compileStates = CompileStates.instance(context);
+
+        try {
+            // catch completion problems with predefineds
+            syms = Symtab.instance(context);
+        } catch (CompletionFailure ex) {
+            // inlined Check.completionError as it is not initialized yet
+            log.error(Errors.CantAccess(ex.sym, ex.getDetailValue()));
+        }
+        source = Source.instance(context);
+        attr = Attr.instance(context);
+        analyzer = Analyzer.instance(context);
+        chk = Check.instance(context);
+        gen = Gen.instance(context);
+        flow = Flow.instance(context);
+        transTypes = TransTypes.instance(context);
+        lower = Lower.instance(context);
+        annotate = Annotate.instance(context);
+        types = Types.instance(context);
+        taskListener = MultiTaskListener.instance(context);
+        modules = Modules.instance(context);
+        moduleFinder = ModuleFinder.instance(context);
+        diags = Factory.instance(context);
+
+        finder.sourceCompleter = sourceCompleter;
+        modules.findPackageInFile = this::findPackageInFile;
+        moduleFinder.moduleNameFromSourceReader = this::readModuleName;
+
+        options = Options.instance(context);
+
+        verbose       = options.isSet(VERBOSE);
+        sourceOutput  = options.isSet(PRINTSOURCE); // used to be -s
+        lineDebugInfo = options.isUnset(G_CUSTOM) ||
+                        options.isSet(G_CUSTOM, "lines");
+        genEndPos     = options.isSet(XJCOV) ||
+                        context.get(DiagnosticListener.class) != null;
+        devVerbose    = options.isSet("dev");
+        processPcks   = options.isSet("process.packages");
+        werror        = options.isSet(WERROR);
+
+        verboseCompilePolicy = options.isSet("verboseCompilePolicy");
+
+        if (options.isSet("should-stop.at") &&
+            CompileState.valueOf(options.get("should-stop.at")) == CompileState.ATTR)
+            compilePolicy = CompilePolicy.ATTR_ONLY;
+        else
+            compilePolicy = CompilePolicy.decode(options.get("compilePolicy"));
+
+        implicitSourcePolicy = ImplicitSourcePolicy.decode(options.get("-implicit"));
+
+        completionFailureName =
+            options.isSet("failcomplete")
+            ? names.fromString(options.get("failcomplete"))
+            : null;
+
+        shouldStopPolicyIfError =
+            options.isSet("should-stop.at") // backwards compatible
+            ? CompileState.valueOf(options.get("should-stop.at"))
+            : options.isSet("should-stop.ifError")
+            ? CompileState.valueOf(options.get("should-stop.ifError"))
+            : CompileState.INIT;
+        shouldStopPolicyIfNoError =
+            options.isSet("should-stop.ifNoError")
+            ? CompileState.valueOf(options.get("should-stop.ifNoError"))
+            : CompileState.GENERATE;
+
+        if (options.isUnset("diags.legacy"))
+            log.setDiagnosticFormatter(RichDiagnosticFormatter.instance(context));
+
+        PlatformDescription platformProvider = context.get(PlatformDescription.class);
+
+        if (platformProvider != null)
+            closeables = closeables.prepend(platformProvider);
+
+        silentFail = new Symbol(ABSENT_TYP, 0, names.empty, Type.noType, syms.rootPackage) {
+            @DefinedBy(Api.LANGUAGE_MODEL)
+            public <R, P> R accept(ElementVisitor<R, P> v, P p) {
+                return v.visitUnknown(this, p);
+            }
+            @Override
+            public boolean exists() {
+                return false;
+            }
+        };
+
+    }
+
+    /* Switches:
+     */
+
+    /** Verbose output.
+     */
+    public boolean verbose;
+
+    /** Emit plain Java source files rather than class files.
+     */
+    public boolean sourceOutput;
+
+
+    /** Generate code with the LineNumberTable attribute for debugging
+     */
+    public boolean lineDebugInfo;
+
+    /** Switch: should we store the ending positions?
+     */
+    public boolean genEndPos;
+
+    /** Switch: should we debug ignored exceptions
+     */
+    protected boolean devVerbose;
+
+    /** Switch: should we (annotation) process packages as well
+     */
+    protected boolean processPcks;
+
+    /** Switch: treat warnings as errors
+     */
+    protected boolean werror;
+
+    /** Switch: is annotation processing requested explicitly via
+     * CompilationTask.setProcessors?
+     */
+    protected boolean explicitAnnotationProcessingRequested = false;
+
+    /**
+     * The policy for the order in which to perform the compilation
+     */
+    protected CompilePolicy compilePolicy;
+
+    /**
+     * The policy for what to do with implicitly read source files
+     */
+    protected ImplicitSourcePolicy implicitSourcePolicy;
+
+    /**
+     * Report activity related to compilePolicy
+     */
+    public boolean verboseCompilePolicy;
+
+    /**
+     * Policy of how far to continue compilation after errors have occurred.
+     * Set this to minimum CompileState (INIT) to stop as soon as possible
+     * after errors.
+     */
+    public CompileState shouldStopPolicyIfError;
+
+    /**
+     * Policy of how far to continue compilation when no errors have occurred.
+     * Set this to maximum CompileState (GENERATE) to perform full compilation.
+     * Set this lower to perform partial compilation, such as -proc:only.
+     */
+    public CompileState shouldStopPolicyIfNoError;
+
+    /** A queue of all as yet unattributed classes.
+     */
+    public Todo todo;
+
+    /** A list of items to be closed when the compilation is complete.
+     */
+    public List<Closeable> closeables = List.nil();
+
+    /** The set of currently compiled inputfiles, needed to ensure
+     *  we don't accidentally overwrite an input file when -s is set.
+     *  initialized by `compile'.
+     */
+    protected Set<JavaFileObject> inputFiles = new HashSet<>();
+
+    /** Used by the resolveBinaryNameOrIdent to say that the given type cannot be found, and that
+     *  an error has already been produced about that.
+     */
+    private final Symbol silentFail;
+
+    protected boolean shouldStop(CompileState cs) {
+        CompileState shouldStopPolicy = (errorCount() > 0 || unrecoverableError())
+            ? shouldStopPolicyIfError
+            : shouldStopPolicyIfNoError;
+        return cs.isAfter(shouldStopPolicy);
+    }
+
+    /** The number of errors reported so far.
+     */
+    public int errorCount() {
+        if (werror && log.nerrors == 0 && log.nwarnings > 0) {
+            log.error(Errors.WarningsAndWerror);
+        }
+        return log.nerrors;
+    }
+
+    protected final <T> Queue<T> stopIfError(CompileState cs, Queue<T> queue) {
+        return shouldStop(cs) ? new ListBuffer<T>() : queue;
+    }
+
+    protected final <T> List<T> stopIfError(CompileState cs, List<T> list) {
+        return shouldStop(cs) ? List.nil() : list;
+    }
+
+    /** The number of warnings reported so far.
+     */
+    public int warningCount() {
+        return log.nwarnings;
+    }
+
+    /** Try to open input stream with given name.
+     *  Report an error if this fails.
+     *  @param filename   The file name of the input stream to be opened.
+     */
+    public CharSequence readSource(JavaFileObject filename) {
+        try {
+            inputFiles.add(filename);
+            return filename.getCharContent(false);
+        } catch (IOException e) {
+            log.error(Errors.ErrorReadingFile(filename, JavacFileManager.getMessage(e)));
+            return null;
+        }
+    }
+
+    /** Parse contents of input stream.
+     *  @param filename     The name of the file from which input stream comes.
+     *  @param content      The characters to be parsed.
+     */
+    protected JCCompilationUnit parse(JavaFileObject filename, CharSequence content) {
+        long msec = now();
+        JCCompilationUnit tree = make.TopLevel(List.nil());
+        if (content != null) {
+            if (verbose) {
+                log.printVerbose("parsing.started", filename);
+            }
+            if (!taskListener.isEmpty()) {
+                TaskEvent e = new TaskEvent(TaskEvent.Kind.PARSE, filename);
+                taskListener.started(e);
+                keepComments = true;
+                genEndPos = true;
+            }
+            Parser parser = parserFactory.newParser(content, keepComments(), genEndPos,
+                                lineDebugInfo, filename.isNameCompatible("module-info", Kind.SOURCE));
+            tree = parser.parseCompilationUnit();
+            if (verbose) {
+                log.printVerbose("parsing.done", Long.toString(elapsed(msec)));
+            }
+        }
+
+        tree.sourcefile = filename;
+
+        if (content != null && !taskListener.isEmpty()) {
+            TaskEvent e = new TaskEvent(TaskEvent.Kind.PARSE, tree);
+            taskListener.finished(e);
+        }
+
+        return tree;
+    }
+    // where
+        public boolean keepComments = false;
+        protected boolean keepComments() {
+            return keepComments || sourceOutput;
+        }
+
+
+    /** Parse contents of file.
+     *  @param filename     The name of the file to be parsed.
+     */
+    @Deprecated
+    public JCTree.JCCompilationUnit parse(String filename) {
+        JavacFileManager fm = (JavacFileManager)fileManager;
+        return parse(fm.getJavaFileObjectsFromStrings(List.of(filename)).iterator().next());
+    }
+
+    /** Parse contents of file.
+     *  @param filename     The name of the file to be parsed.
+     */
+    public JCTree.JCCompilationUnit parse(JavaFileObject filename) {
+        JavaFileObject prev = log.useSource(filename);
+        try {
+            JCTree.JCCompilationUnit t = parse(filename, readSource(filename));
+            if (t.endPositions != null)
+                log.setEndPosTable(filename, t.endPositions);
+            return t;
+        } finally {
+            log.useSource(prev);
+        }
+    }
+
+    /** Resolve an identifier which may be the binary name of a class or
+     * the Java name of a class or package.
+     * @param name      The name to resolve
+     */
+    public Symbol resolveBinaryNameOrIdent(String name) {
+        ModuleSymbol msym;
+        String typeName;
+        int sep = name.indexOf('/');
+        if (sep == -1) {
+            msym = modules.getDefaultModule();
+            typeName = name;
+        } else if (source.allowModules()) {
+            Name modName = names.fromString(name.substring(0, sep));
+
+            msym = moduleFinder.findModule(modName);
+            typeName = name.substring(sep + 1);
+        } else {
+            log.error(Errors.InvalidModuleSpecifier(name));
+            return silentFail;
+        }
+
+        return resolveBinaryNameOrIdent(msym, typeName);
+    }
+
+    /** Resolve an identifier which may be the binary name of a class or
+     * the Java name of a class or package.
+     * @param msym      The module in which the search should be performed
+     * @param name      The name to resolve
+     */
+    public Symbol resolveBinaryNameOrIdent(ModuleSymbol msym, String name) {
+        try {
+            Name flatname = names.fromString(name.replace("/", "."));
+            return finder.loadClass(msym, flatname);
+        } catch (CompletionFailure ignore) {
+            return resolveIdent(msym, name);
+        }
+    }
+
+    /** Resolve an identifier.
+     * @param msym      The module in which the search should be performed
+     * @param name      The identifier to resolve
+     */
+    public Symbol resolveIdent(ModuleSymbol msym, String name) {
+        if (name.equals(""))
+            return syms.errSymbol;
+        JavaFileObject prev = log.useSource(null);
+        try {
+            JCExpression tree = null;
+            for (String s : name.split("\\.", -1)) {
+                if (!SourceVersion.isIdentifier(s)) // TODO: check for keywords
+                    return syms.errSymbol;
+                tree = (tree == null) ? make.Ident(names.fromString(s))
+                                      : make.Select(tree, names.fromString(s));
+            }
+            JCCompilationUnit toplevel =
+                make.TopLevel(List.nil());
+            toplevel.modle = msym;
+            toplevel.packge = msym.unnamedPackage;
+            return attr.attribIdent(tree, toplevel);
+        } finally {
+            log.useSource(prev);
+        }
+    }
+
+    /** Generate code and emit a class file for a given class
+     *  @param env    The attribution environment of the outermost class
+     *                containing this class.
+     *  @param cdef   The class definition from which code is generated.
+     */
+    JavaFileObject genCode(Env<AttrContext> env, JCClassDecl cdef) throws IOException {
+        try {
+            if (gen.genClass(env, cdef) && (errorCount() == 0))
+                return writer.writeClass(cdef.sym);
+        } catch (ClassWriter.PoolOverflow ex) {
+            log.error(cdef.pos(), Errors.LimitPool);
+        } catch (ClassWriter.StringOverflow ex) {
+            log.error(cdef.pos(),
+                      Errors.LimitStringOverflow(ex.value.substring(0, 20)));
+        } catch (CompletionFailure ex) {
+            chk.completionError(cdef.pos(), ex);
+        }
+        return null;
+    }
+
+    /** Emit plain Java source for a class.
+     *  @param env    The attribution environment of the outermost class
+     *                containing this class.
+     *  @param cdef   The class definition to be printed.
+     */
+    JavaFileObject printSource(Env<AttrContext> env, JCClassDecl cdef) throws IOException {
+        JavaFileObject outFile
+           = fileManager.getJavaFileForOutput(CLASS_OUTPUT,
+                                               cdef.sym.flatname.toString(),
+                                               JavaFileObject.Kind.SOURCE,
+                                               null);
+        if (inputFiles.contains(outFile)) {
+            log.error(cdef.pos(), Errors.SourceCantOverwriteInputFile(outFile));
+            return null;
+        } else {
+            try (BufferedWriter out = new BufferedWriter(outFile.openWriter())) {
+                new Pretty(out, true).printUnit(env.toplevel, cdef);
+                if (verbose)
+                    log.printVerbose("wrote.file", outFile);
+            }
+            return outFile;
+        }
+    }
+
+    /** Compile a source file that has been accessed by the class finder.
+     *  @param c          The class the source file of which needs to be compiled.
+     */
+    private void readSourceFile(ClassSymbol c) throws CompletionFailure {
+        readSourceFile(null, c);
+    }
+
+    /** Compile a ClassSymbol from source, optionally using the given compilation unit as
+     *  the source tree.
+     *  @param tree the compilation unit in which the given ClassSymbol resides,
+     *              or null if should be parsed from source
+     *  @param c    the ClassSymbol to complete
+     */
+    public void readSourceFile(JCCompilationUnit tree, ClassSymbol c) throws CompletionFailure {
+        if (completionFailureName == c.fullname) {
+            JCDiagnostic msg =
+                    diagFactory.fragment(Fragments.UserSelectedCompletionFailure);
+            throw new CompletionFailure(c, msg);
+        }
+        JavaFileObject filename = c.classfile;
+        JavaFileObject prev = log.useSource(filename);
+
+        if (tree == null) {
+            try {
+                tree = parse(filename, filename.getCharContent(false));
+            } catch (IOException e) {
+                log.error(Errors.ErrorReadingFile(filename, JavacFileManager.getMessage(e)));
+                tree = make.TopLevel(List.<JCTree>nil());
+            } finally {
+                log.useSource(prev);
+            }
+        }
+
+        if (!taskListener.isEmpty()) {
+            TaskEvent e = new TaskEvent(TaskEvent.Kind.ENTER, tree);
+            taskListener.started(e);
+        }
+
+        // Process module declarations.
+        // If module resolution fails, ignore trees, and if trying to
+        // complete a specific symbol, throw CompletionFailure.
+        // Note that if module resolution failed, we may not even
+        // have enough modules available to access java.lang, and
+        // so risk getting FatalError("no.java.lang") from MemberEnter.
+        if (!modules.enter(List.of(tree), c)) {
+            throw new CompletionFailure(c, diags.fragment(Fragments.CantResolveModules));
+        }
+
+        enter.complete(List.of(tree), c);
+
+        if (!taskListener.isEmpty()) {
+            TaskEvent e = new TaskEvent(TaskEvent.Kind.ENTER, tree);
+            taskListener.finished(e);
+        }
+
+        if (enter.getEnv(c) == null) {
+            boolean isPkgInfo =
+                tree.sourcefile.isNameCompatible("package-info",
+                                                 JavaFileObject.Kind.SOURCE);
+            boolean isModuleInfo =
+                tree.sourcefile.isNameCompatible("module-info",
+                                                 JavaFileObject.Kind.SOURCE);
+            if (isModuleInfo) {
+                if (enter.getEnv(tree.modle) == null) {
+                    JCDiagnostic diag =
+                        diagFactory.fragment(Fragments.FileDoesNotContainModule);
+                    throw new ClassFinder.BadClassFile(c, filename, diag, diagFactory);
+                }
+            } else if (isPkgInfo) {
+                if (enter.getEnv(tree.packge) == null) {
+                    JCDiagnostic diag =
+                        diagFactory.fragment(Fragments.FileDoesNotContainPackage(c.location()));
+                    throw new ClassFinder.BadClassFile(c, filename, diag, diagFactory);
+                }
+            } else {
+                JCDiagnostic diag =
+                        diagFactory.fragment(Fragments.FileDoesntContainClass(c.getQualifiedName()));
+                throw new ClassFinder.BadClassFile(c, filename, diag, diagFactory);
+            }
+        }
+
+        implicitSourceFilesRead = true;
+    }
+
+    /** Track when the JavaCompiler has been used to compile something. */
+    private boolean hasBeenUsed = false;
+    private long start_msec = 0;
+    public long elapsed_msec = 0;
+
+    public void compile(List<JavaFileObject> sourceFileObject)
+        throws Throwable {
+        compile(sourceFileObject, List.nil(), null, List.nil());
+    }
+
+    /**
+     * Main method: compile a list of files, return all compiled classes
+     *
+     * @param sourceFileObjects file objects to be compiled
+     * @param classnames class names to process for annotations
+     * @param processors user provided annotation processors to bypass
+     * discovery, {@code null} means that no processors were provided
+     * @param addModules additional root modules to be used during
+     * module resolution.
+     */
+    public void compile(Collection<JavaFileObject> sourceFileObjects,
+                        Collection<String> classnames,
+                        Iterable<? extends Processor> processors,
+                        Collection<String> addModules)
+    {
+        if (!taskListener.isEmpty()) {
+            taskListener.started(new TaskEvent(TaskEvent.Kind.COMPILATION));
+        }
+
+        if (processors != null && processors.iterator().hasNext())
+            explicitAnnotationProcessingRequested = true;
+        // as a JavaCompiler can only be used once, throw an exception if
+        // it has been used before.
+        if (hasBeenUsed)
+            checkReusable();
+        hasBeenUsed = true;
+
+        // forcibly set the equivalent of -Xlint:-options, so that no further
+        // warnings about command line options are generated from this point on
+        options.put(XLINT_CUSTOM.primaryName + "-" + LintCategory.OPTIONS.option, "true");
+        options.remove(XLINT_CUSTOM.primaryName + LintCategory.OPTIONS.option);
+
+        start_msec = now();
+
+        try {
+            initProcessAnnotations(processors, sourceFileObjects, classnames);
+
+            for (String className : classnames) {
+                int sep = className.indexOf('/');
+                if (sep != -1) {
+                    modules.addExtraAddModules(className.substring(0, sep));
+                }
+            }
+
+            for (String moduleName : addModules) {
+                modules.addExtraAddModules(moduleName);
+            }
+
+            // These method calls must be chained to avoid memory leaks
+            processAnnotations(
+                enterTrees(
+                        stopIfError(CompileState.PARSE,
+                                initModules(stopIfError(CompileState.PARSE, parseFiles(sourceFileObjects))))
+                ),
+                classnames
+            );
+
+            // If it's safe to do so, skip attr / flow / gen for implicit classes
+            if (taskListener.isEmpty() &&
+                    implicitSourcePolicy == ImplicitSourcePolicy.NONE) {
+                todo.retainFiles(inputFiles);
+            }
+
+            switch (compilePolicy) {
+            case ATTR_ONLY:
+                attribute(todo);
+                break;
+
+            case CHECK_ONLY:
+                flow(attribute(todo));
+                break;
+
+            case SIMPLE:
+                generate(desugar(flow(attribute(todo))));
+                break;
+
+            case BY_FILE: {
+                    Queue<Queue<Env<AttrContext>>> q = todo.groupByFile();
+                    while (!q.isEmpty() && !shouldStop(CompileState.ATTR)) {
+                        generate(desugar(flow(attribute(q.remove()))));
+                    }
+                }
+                break;
+
+            case BY_TODO:
+                while (!todo.isEmpty())
+                    generate(desugar(flow(attribute(todo.remove()))));
+                break;
+
+            default:
+                Assert.error("unknown compile policy");
+            }
+        } catch (Abort ex) {
+            if (devVerbose)
+                ex.printStackTrace(System.err);
+        } finally {
+            if (verbose) {
+                elapsed_msec = elapsed(start_msec);
+                log.printVerbose("total", Long.toString(elapsed_msec));
+            }
+
+            reportDeferredDiagnostics();
+
+            if (!log.hasDiagnosticListener()) {
+                printCount("error", errorCount());
+                printCount("warn", warningCount());
+            }
+            if (!taskListener.isEmpty()) {
+                taskListener.finished(new TaskEvent(TaskEvent.Kind.COMPILATION));
+            }
+            close();
+            if (procEnvImpl != null)
+                procEnvImpl.close();
+        }
+    }
+
+    protected void checkReusable() {
+        throw new AssertionError("attempt to reuse JavaCompiler");
+    }
+
+    /**
+     * The list of classes explicitly supplied on the command line for compilation.
+     * Not always populated.
+     */
+    private List<JCClassDecl> rootClasses;
+
+    /**
+     * Parses a list of files.
+     */
+   public List<JCCompilationUnit> parseFiles(Iterable<JavaFileObject> fileObjects) {
+       if (shouldStop(CompileState.PARSE))
+           return List.nil();
+
+        //parse all files
+        ListBuffer<JCCompilationUnit> trees = new ListBuffer<>();
+        Set<JavaFileObject> filesSoFar = new HashSet<>();
+        for (JavaFileObject fileObject : fileObjects) {
+            if (!filesSoFar.contains(fileObject)) {
+                filesSoFar.add(fileObject);
+                trees.append(parse(fileObject));
+            }
+        }
+        return trees.toList();
+    }
+
+    /**
+     * Enter the symbols found in a list of parse trees if the compilation
+     * is expected to proceed beyond anno processing into attr.
+     * As a side-effect, this puts elements on the "todo" list.
+     * Also stores a list of all top level classes in rootClasses.
+     */
+    public List<JCCompilationUnit> enterTreesIfNeeded(List<JCCompilationUnit> roots) {
+       if (shouldStop(CompileState.ATTR))
+           return List.nil();
+        return enterTrees(initModules(roots));
+    }
+
+    public List<JCCompilationUnit> initModules(List<JCCompilationUnit> roots) {
+        modules.initModules(roots);
+        if (roots.isEmpty()) {
+            enterDone();
+        }
+        return roots;
+    }
+
+    /**
+     * Enter the symbols found in a list of parse trees.
+     * As a side-effect, this puts elements on the "todo" list.
+     * Also stores a list of all top level classes in rootClasses.
+     */
+    public List<JCCompilationUnit> enterTrees(List<JCCompilationUnit> roots) {
+        //enter symbols for all files
+        if (!taskListener.isEmpty()) {
+            for (JCCompilationUnit unit: roots) {
+                TaskEvent e = new TaskEvent(TaskEvent.Kind.ENTER, unit);
+                taskListener.started(e);
+            }
+        }
+
+        enter.main(roots);
+
+        enterDone();
+
+        if (!taskListener.isEmpty()) {
+            for (JCCompilationUnit unit: roots) {
+                TaskEvent e = new TaskEvent(TaskEvent.Kind.ENTER, unit);
+                taskListener.finished(e);
+            }
+        }
+
+        // If generating source, or if tracking public apis,
+        // then remember the classes declared in
+        // the original compilation units listed on the command line.
+        if (sourceOutput) {
+            ListBuffer<JCClassDecl> cdefs = new ListBuffer<>();
+            for (JCCompilationUnit unit : roots) {
+                for (List<JCTree> defs = unit.defs;
+                     defs.nonEmpty();
+                     defs = defs.tail) {
+                    if (defs.head instanceof JCClassDecl)
+                        cdefs.append((JCClassDecl)defs.head);
+                }
+            }
+            rootClasses = cdefs.toList();
+        }
+
+        // Ensure the input files have been recorded. Although this is normally
+        // done by readSource, it may not have been done if the trees were read
+        // in a prior round of annotation processing, and the trees have been
+        // cleaned and are being reused.
+        for (JCCompilationUnit unit : roots) {
+            inputFiles.add(unit.sourcefile);
+        }
+
+        return roots;
+    }
+
+    /**
+     * Set to true to enable skeleton annotation processing code.
+     * Currently, we assume this variable will be replaced more
+     * advanced logic to figure out if annotation processing is
+     * needed.
+     */
+    boolean processAnnotations = false;
+
+    Log.DeferredDiagnosticHandler deferredDiagnosticHandler;
+
+    /**
+     * Object to handle annotation processing.
+     */
+    private JavacProcessingEnvironment procEnvImpl = null;
+
+    /**
+     * Check if we should process annotations.
+     * If so, and if no scanner is yet registered, then set up the DocCommentScanner
+     * to catch doc comments, and set keepComments so the parser records them in
+     * the compilation unit.
+     *
+     * @param processors user provided annotation processors to bypass
+     * discovery, {@code null} means that no processors were provided
+     */
+    public void initProcessAnnotations(Iterable<? extends Processor> processors,
+                                       Collection<? extends JavaFileObject> initialFiles,
+                                       Collection<String> initialClassNames) {
+        // Process annotations if processing is not disabled and there
+        // is at least one Processor available.
+        if (options.isSet(PROC, "none")) {
+            processAnnotations = false;
+        } else if (procEnvImpl == null) {
+            procEnvImpl = JavacProcessingEnvironment.instance(context);
+            procEnvImpl.setProcessors(processors);
+            processAnnotations = procEnvImpl.atLeastOneProcessor();
+
+            if (processAnnotations) {
+                options.put("parameters", "parameters");
+                reader.saveParameterNames = true;
+                keepComments = true;
+                genEndPos = true;
+                if (!taskListener.isEmpty())
+                    taskListener.started(new TaskEvent(TaskEvent.Kind.ANNOTATION_PROCESSING));
+                deferredDiagnosticHandler = new Log.DeferredDiagnosticHandler(log);
+                procEnvImpl.getFiler().setInitialState(initialFiles, initialClassNames);
+            } else { // free resources
+                procEnvImpl.close();
+            }
+        }
+    }
+
+    // TODO: called by JavacTaskImpl
+    public void processAnnotations(List<JCCompilationUnit> roots) {
+        processAnnotations(roots, List.nil());
+    }
+
+    /**
+     * Process any annotations found in the specified compilation units.
+     * @param roots a list of compilation units
+     */
+    // Implementation note: when this method is called, log.deferredDiagnostics
+    // will have been set true by initProcessAnnotations, meaning that any diagnostics
+    // that are reported will go into the log.deferredDiagnostics queue.
+    // By the time this method exits, log.deferDiagnostics must be set back to false,
+    // and all deferredDiagnostics must have been handled: i.e. either reported
+    // or determined to be transient, and therefore suppressed.
+    public void processAnnotations(List<JCCompilationUnit> roots,
+                                   Collection<String> classnames) {
+        if (shouldStop(CompileState.PROCESS)) {
+            // Errors were encountered.
+            // Unless all the errors are resolve errors, the errors were parse errors
+            // or other errors during enter which cannot be fixed by running
+            // any annotation processors.
+            if (unrecoverableError()) {
+                deferredDiagnosticHandler.reportDeferredDiagnostics();
+                log.popDiagnosticHandler(deferredDiagnosticHandler);
+                return ;
+            }
+        }
+
+        // ASSERT: processAnnotations and procEnvImpl should have been set up by
+        // by initProcessAnnotations
+
+        // NOTE: The !classnames.isEmpty() checks should be refactored to Main.
+
+        if (!processAnnotations) {
+            // If there are no annotation processors present, and
+            // annotation processing is to occur with compilation,
+            // emit a warning.
+            if (options.isSet(PROC, "only")) {
+                log.warning(Warnings.ProcProcOnlyRequestedNoProcs);
+                todo.clear();
+            }
+            // If not processing annotations, classnames must be empty
+            if (!classnames.isEmpty()) {
+                log.error(Errors.ProcNoExplicitAnnotationProcessingRequested(classnames));
+            }
+            Assert.checkNull(deferredDiagnosticHandler);
+            return ; // continue regular compilation
+        }
+
+        Assert.checkNonNull(deferredDiagnosticHandler);
+
+        try {
+            List<ClassSymbol> classSymbols = List.nil();
+            List<PackageSymbol> pckSymbols = List.nil();
+            if (!classnames.isEmpty()) {
+                 // Check for explicit request for annotation
+                 // processing
+                if (!explicitAnnotationProcessingRequested()) {
+                    log.error(Errors.ProcNoExplicitAnnotationProcessingRequested(classnames));
+                    deferredDiagnosticHandler.reportDeferredDiagnostics();
+                    log.popDiagnosticHandler(deferredDiagnosticHandler);
+                    return ; // TODO: Will this halt compilation?
+                } else {
+                    boolean errors = false;
+                    for (String nameStr : classnames) {
+                        Symbol sym = resolveBinaryNameOrIdent(nameStr);
+                        if (sym == null ||
+                            (sym.kind == PCK && !processPcks) ||
+                            sym.kind == ABSENT_TYP) {
+                            if (sym != silentFail)
+                                log.error(Errors.ProcCantFindClass(nameStr));
+                            errors = true;
+                            continue;
+                        }
+                        try {
+                            if (sym.kind == PCK)
+                                sym.complete();
+                            if (sym.exists()) {
+                                if (sym.kind == PCK)
+                                    pckSymbols = pckSymbols.prepend((PackageSymbol)sym);
+                                else
+                                    classSymbols = classSymbols.prepend((ClassSymbol)sym);
+                                continue;
+                            }
+                            Assert.check(sym.kind == PCK);
+                            log.warning(Warnings.ProcPackageDoesNotExist(nameStr));
+                            pckSymbols = pckSymbols.prepend((PackageSymbol)sym);
+                        } catch (CompletionFailure e) {
+                            log.error(Errors.ProcCantFindClass(nameStr));
+                            errors = true;
+                            continue;
+                        }
+                    }
+                    if (errors) {
+                        deferredDiagnosticHandler.reportDeferredDiagnostics();
+                        log.popDiagnosticHandler(deferredDiagnosticHandler);
+                        return ;
+                    }
+                }
+            }
+            try {
+                annotationProcessingOccurred =
+                        procEnvImpl.doProcessing(roots,
+                                                 classSymbols,
+                                                 pckSymbols,
+                                                 deferredDiagnosticHandler);
+                // doProcessing will have handled deferred diagnostics
+            } finally {
+                procEnvImpl.close();
+            }
+        } catch (CompletionFailure ex) {
+            log.error(Errors.CantAccess(ex.sym, ex.getDetailValue()));
+            if (deferredDiagnosticHandler != null) {
+                deferredDiagnosticHandler.reportDeferredDiagnostics();
+                log.popDiagnosticHandler(deferredDiagnosticHandler);
+            }
+        }
+    }
+
+    private boolean unrecoverableError() {
+        if (deferredDiagnosticHandler != null) {
+            for (JCDiagnostic d: deferredDiagnosticHandler.getDiagnostics()) {
+                if (d.getKind() == JCDiagnostic.Kind.ERROR && !d.isFlagSet(RECOVERABLE))
+                    return true;
+            }
+        }
+        return false;
+    }
+
+    boolean explicitAnnotationProcessingRequested() {
+        return
+            explicitAnnotationProcessingRequested ||
+            explicitAnnotationProcessingRequested(options);
+    }
+
+    static boolean explicitAnnotationProcessingRequested(Options options) {
+        return
+            options.isSet(PROCESSOR) ||
+            options.isSet(PROCESSOR_PATH) ||
+            options.isSet(PROCESSOR_MODULE_PATH) ||
+            options.isSet(PROC, "only") ||
+            options.isSet(XPRINT);
+    }
+
+    public void setDeferredDiagnosticHandler(Log.DeferredDiagnosticHandler deferredDiagnosticHandler) {
+        this.deferredDiagnosticHandler = deferredDiagnosticHandler;
+    }
+
+    /**
+     * Attribute a list of parse trees, such as found on the "todo" list.
+     * Note that attributing classes may cause additional files to be
+     * parsed and entered via the SourceCompleter.
+     * Attribution of the entries in the list does not stop if any errors occur.
+     * @return a list of environments for attribute classes.
+     */
+    public Queue<Env<AttrContext>> attribute(Queue<Env<AttrContext>> envs) {
+        ListBuffer<Env<AttrContext>> results = new ListBuffer<>();
+        while (!envs.isEmpty())
+            results.append(attribute(envs.remove()));
+        return stopIfError(CompileState.ATTR, results);
+    }
+
+    /**
+     * Attribute a parse tree.
+     * @return the attributed parse tree
+     */
+    public Env<AttrContext> attribute(Env<AttrContext> env) {
+        if (compileStates.isDone(env, CompileState.ATTR))
+            return env;
+
+        if (verboseCompilePolicy)
+            printNote("[attribute " + env.enclClass.sym + "]");
+        if (verbose)
+            log.printVerbose("checking.attribution", env.enclClass.sym);
+
+        if (!taskListener.isEmpty()) {
+            TaskEvent e = new TaskEvent(TaskEvent.Kind.ANALYZE, env.toplevel, env.enclClass.sym);
+            taskListener.started(e);
+        }
+
+        JavaFileObject prev = log.useSource(
+                                  env.enclClass.sym.sourcefile != null ?
+                                  env.enclClass.sym.sourcefile :
+                                  env.toplevel.sourcefile);
+        try {
+            attr.attrib(env);
+            if (errorCount() > 0 && !shouldStop(CompileState.ATTR)) {
+                //if in fail-over mode, ensure that AST expression nodes
+                //are correctly initialized (e.g. they have a type/symbol)
+                attr.postAttr(env.tree);
+            }
+            compileStates.put(env, CompileState.ATTR);
+        }
+        finally {
+            log.useSource(prev);
+        }
+
+        return env;
+    }
+
+    /**
+     * Perform dataflow checks on attributed parse trees.
+     * These include checks for definite assignment and unreachable statements.
+     * If any errors occur, an empty list will be returned.
+     * @return the list of attributed parse trees
+     */
+    public Queue<Env<AttrContext>> flow(Queue<Env<AttrContext>> envs) {
+        ListBuffer<Env<AttrContext>> results = new ListBuffer<>();
+        for (Env<AttrContext> env: envs) {
+            flow(env, results);
+        }
+        return stopIfError(CompileState.FLOW, results);
+    }
+
+    /**
+     * Perform dataflow checks on an attributed parse tree.
+     */
+    public Queue<Env<AttrContext>> flow(Env<AttrContext> env) {
+        ListBuffer<Env<AttrContext>> results = new ListBuffer<>();
+        flow(env, results);
+        return stopIfError(CompileState.FLOW, results);
+    }
+
+    /**
+     * Perform dataflow checks on an attributed parse tree.
+     */
+    protected void flow(Env<AttrContext> env, Queue<Env<AttrContext>> results) {
+        if (compileStates.isDone(env, CompileState.FLOW)) {
+            results.add(env);
+            return;
+        }
+
+        try {
+            if (shouldStop(CompileState.FLOW))
+                return;
+
+            if (verboseCompilePolicy)
+                printNote("[flow " + env.enclClass.sym + "]");
+            JavaFileObject prev = log.useSource(
+                                                env.enclClass.sym.sourcefile != null ?
+                                                env.enclClass.sym.sourcefile :
+                                                env.toplevel.sourcefile);
+            try {
+                make.at(Position.FIRSTPOS);
+                TreeMaker localMake = make.forToplevel(env.toplevel);
+                flow.analyzeTree(env, localMake);
+                compileStates.put(env, CompileState.FLOW);
+
+                if (shouldStop(CompileState.FLOW))
+                    return;
+
+                analyzer.flush(env);
+
+                results.add(env);
+            }
+            finally {
+                log.useSource(prev);
+            }
+        }
+        finally {
+            if (!taskListener.isEmpty()) {
+                TaskEvent e = new TaskEvent(TaskEvent.Kind.ANALYZE, env.toplevel, env.enclClass.sym);
+                taskListener.finished(e);
+            }
+        }
+    }
+
+    /**
+     * Prepare attributed parse trees, in conjunction with their attribution contexts,
+     * for source or code generation.
+     * If any errors occur, an empty list will be returned.
+     * @return a list containing the classes to be generated
+     */
+    public Queue<Pair<Env<AttrContext>, JCClassDecl>> desugar(Queue<Env<AttrContext>> envs) {
+        ListBuffer<Pair<Env<AttrContext>, JCClassDecl>> results = new ListBuffer<>();
+        for (Env<AttrContext> env: envs)
+            desugar(env, results);
+        return stopIfError(CompileState.FLOW, results);
+    }
+
+    HashMap<Env<AttrContext>, Queue<Pair<Env<AttrContext>, JCClassDecl>>> desugaredEnvs = new HashMap<>();
+
+    /**
+     * Prepare attributed parse trees, in conjunction with their attribution contexts,
+     * for source or code generation. If the file was not listed on the command line,
+     * the current implicitSourcePolicy is taken into account.
+     * The preparation stops as soon as an error is found.
+     */
+    protected void desugar(final Env<AttrContext> env, Queue<Pair<Env<AttrContext>, JCClassDecl>> results) {
+        if (shouldStop(CompileState.TRANSTYPES))
+            return;
+
+        if (implicitSourcePolicy == ImplicitSourcePolicy.NONE
+                && !inputFiles.contains(env.toplevel.sourcefile)) {
+            return;
+        }
+
+        if (!modules.multiModuleMode && env.toplevel.modle != modules.getDefaultModule()) {
+            //can only generate classfiles for a single module:
+            return;
+        }
+
+        if (compileStates.isDone(env, CompileState.LOWER)) {
+            results.addAll(desugaredEnvs.get(env));
+            return;
+        }
+
+        /**
+         * Ensure that superclasses of C are desugared before C itself. This is
+         * required for two reasons: (i) as erasure (TransTypes) destroys
+         * information needed in flow analysis and (ii) as some checks carried
+         * out during lowering require that all synthetic fields/methods have
+         * already been added to C and its superclasses.
+         */
+        class ScanNested extends TreeScanner {
+            Set<Env<AttrContext>> dependencies = new LinkedHashSet<>();
+            protected boolean hasLambdas;
+            @Override
+            public void visitClassDef(JCClassDecl node) {
+                Type st = types.supertype(node.sym.type);
+                boolean envForSuperTypeFound = false;
+                while (!envForSuperTypeFound && st.hasTag(CLASS)) {
+                    ClassSymbol c = st.tsym.outermostClass();
+                    Env<AttrContext> stEnv = enter.getEnv(c);
+                    if (stEnv != null && env != stEnv) {
+                        if (dependencies.add(stEnv)) {
+                            boolean prevHasLambdas = hasLambdas;
+                            try {
+                                scan(stEnv.tree);
+                            } finally {
+                                /*
+                                 * ignore any updates to hasLambdas made during
+                                 * the nested scan, this ensures an initalized
+                                 * LambdaToMethod is available only to those
+                                 * classes that contain lambdas
+                                 */
+                                hasLambdas = prevHasLambdas;
+                            }
+                        }
+                        envForSuperTypeFound = true;
+                    }
+                    st = types.supertype(st);
+                }
+                super.visitClassDef(node);
+            }
+            @Override
+            public void visitLambda(JCLambda tree) {
+                hasLambdas = true;
+                super.visitLambda(tree);
+            }
+            @Override
+            public void visitReference(JCMemberReference tree) {
+                hasLambdas = true;
+                super.visitReference(tree);
+            }
+        }
+        ScanNested scanner = new ScanNested();
+        scanner.scan(env.tree);
+        for (Env<AttrContext> dep: scanner.dependencies) {
+        if (!compileStates.isDone(dep, CompileState.FLOW))
+            desugaredEnvs.put(dep, desugar(flow(attribute(dep))));
+        }
+
+        //We need to check for error another time as more classes might
+        //have been attributed and analyzed at this stage
+        if (shouldStop(CompileState.TRANSTYPES))
+            return;
+
+        if (verboseCompilePolicy)
+            printNote("[desugar " + env.enclClass.sym + "]");
+
+        JavaFileObject prev = log.useSource(env.enclClass.sym.sourcefile != null ?
+                                  env.enclClass.sym.sourcefile :
+                                  env.toplevel.sourcefile);
+        try {
+            //save tree prior to rewriting
+            JCTree untranslated = env.tree;
+
+            make.at(Position.FIRSTPOS);
+            TreeMaker localMake = make.forToplevel(env.toplevel);
+
+            if (env.tree.hasTag(JCTree.Tag.PACKAGEDEF) || env.tree.hasTag(JCTree.Tag.MODULEDEF)) {
+                if (!(sourceOutput)) {
+                    if (shouldStop(CompileState.LOWER))
+                        return;
+                    List<JCTree> def = lower.translateTopLevelClass(env, env.tree, localMake);
+                    if (def.head != null) {
+                        Assert.check(def.tail.isEmpty());
+                        results.add(new Pair<>(env, (JCClassDecl)def.head));
+                    }
+                }
+                return;
+            }
+
+            if (shouldStop(CompileState.TRANSTYPES))
+                return;
+
+            env.tree = transTypes.translateTopLevelClass(env.tree, localMake);
+            compileStates.put(env, CompileState.TRANSTYPES);
+
+            if (source.allowLambda() && scanner.hasLambdas) {
+                if (shouldStop(CompileState.UNLAMBDA))
+                    return;
+
+                env.tree = LambdaToMethod.instance(context).translateTopLevelClass(env, env.tree, localMake);
+                compileStates.put(env, CompileState.UNLAMBDA);
+            }
+
+            if (shouldStop(CompileState.LOWER))
+                return;
+
+            if (sourceOutput) {
+                //emit standard Java source file, only for compilation
+                //units enumerated explicitly on the command line
+                JCClassDecl cdef = (JCClassDecl)env.tree;
+                if (untranslated instanceof JCClassDecl &&
+                    rootClasses.contains((JCClassDecl)untranslated)) {
+                    results.add(new Pair<>(env, cdef));
+                }
+                return;
+            }
+
+            //translate out inner classes
+            List<JCTree> cdefs = lower.translateTopLevelClass(env, env.tree, localMake);
+            compileStates.put(env, CompileState.LOWER);
+
+            if (shouldStop(CompileState.LOWER))
+                return;
+
+            //generate code for each class
+            for (List<JCTree> l = cdefs; l.nonEmpty(); l = l.tail) {
+                JCClassDecl cdef = (JCClassDecl)l.head;
+                results.add(new Pair<>(env, cdef));
+            }
+        }
+        finally {
+            log.useSource(prev);
+        }
+
+    }
+
+    /** Generates the source or class file for a list of classes.
+     * The decision to generate a source file or a class file is
+     * based upon the compiler's options.
+     * Generation stops if an error occurs while writing files.
+     */
+    public void generate(Queue<Pair<Env<AttrContext>, JCClassDecl>> queue) {
+        generate(queue, null);
+    }
+
+    public void generate(Queue<Pair<Env<AttrContext>, JCClassDecl>> queue, Queue<JavaFileObject> results) {
+        if (shouldStop(CompileState.GENERATE))
+            return;
+
+        for (Pair<Env<AttrContext>, JCClassDecl> x: queue) {
+            Env<AttrContext> env = x.fst;
+            JCClassDecl cdef = x.snd;
+
+            if (verboseCompilePolicy) {
+                printNote("[generate " + (sourceOutput ? " source" : "code") + " " + cdef.sym + "]");
+            }
+
+            if (!taskListener.isEmpty()) {
+                TaskEvent e = new TaskEvent(TaskEvent.Kind.GENERATE, env.toplevel, cdef.sym);
+                taskListener.started(e);
+            }
+
+            JavaFileObject prev = log.useSource(env.enclClass.sym.sourcefile != null ?
+                                      env.enclClass.sym.sourcefile :
+                                      env.toplevel.sourcefile);
+            try {
+                JavaFileObject file;
+                if (sourceOutput) {
+                    file = printSource(env, cdef);
+                } else {
+                    if (fileManager.hasLocation(StandardLocation.NATIVE_HEADER_OUTPUT)
+                            && jniWriter.needsHeader(cdef.sym)) {
+                        jniWriter.write(cdef.sym);
+                    }
+                    file = genCode(env, cdef);
+                }
+                if (results != null && file != null)
+                    results.add(file);
+            } catch (IOException ex) {
+                log.error(cdef.pos(),
+                          Errors.ClassCantWrite(cdef.sym, ex.getMessage()));
+                return;
+            } finally {
+                log.useSource(prev);
+            }
+
+            if (!taskListener.isEmpty()) {
+                TaskEvent e = new TaskEvent(TaskEvent.Kind.GENERATE, env.toplevel, cdef.sym);
+                taskListener.finished(e);
+            }
+        }
+    }
+
+        // where
+        Map<JCCompilationUnit, Queue<Env<AttrContext>>> groupByFile(Queue<Env<AttrContext>> envs) {
+            // use a LinkedHashMap to preserve the order of the original list as much as possible
+            Map<JCCompilationUnit, Queue<Env<AttrContext>>> map = new LinkedHashMap<>();
+            for (Env<AttrContext> env: envs) {
+                Queue<Env<AttrContext>> sublist = map.get(env.toplevel);
+                if (sublist == null) {
+                    sublist = new ListBuffer<>();
+                    map.put(env.toplevel, sublist);
+                }
+                sublist.add(env);
+            }
+            return map;
+        }
+
+        JCClassDecl removeMethodBodies(JCClassDecl cdef) {
+            final boolean isInterface = (cdef.mods.flags & Flags.INTERFACE) != 0;
+            class MethodBodyRemover extends TreeTranslator {
+                @Override
+                public void visitMethodDef(JCMethodDecl tree) {
+                    tree.mods.flags &= ~Flags.SYNCHRONIZED;
+                    for (JCVariableDecl vd : tree.params)
+                        vd.mods.flags &= ~Flags.FINAL;
+                    tree.body = null;
+                    super.visitMethodDef(tree);
+                }
+                @Override
+                public void visitVarDef(JCVariableDecl tree) {
+                    if (tree.init != null && tree.init.type.constValue() == null)
+                        tree.init = null;
+                    super.visitVarDef(tree);
+                }
+                @Override
+                public void visitClassDef(JCClassDecl tree) {
+                    ListBuffer<JCTree> newdefs = new ListBuffer<>();
+                    for (List<JCTree> it = tree.defs; it.tail != null; it = it.tail) {
+                        JCTree t = it.head;
+                        switch (t.getTag()) {
+                        case CLASSDEF:
+                            if (isInterface ||
+                                (((JCClassDecl) t).mods.flags & (Flags.PROTECTED|Flags.PUBLIC)) != 0 ||
+                                (((JCClassDecl) t).mods.flags & (Flags.PRIVATE)) == 0 && ((JCClassDecl) t).sym.packge().getQualifiedName() == names.java_lang)
+                                newdefs.append(t);
+                            break;
+                        case METHODDEF:
+                            if (isInterface ||
+                                (((JCMethodDecl) t).mods.flags & (Flags.PROTECTED|Flags.PUBLIC)) != 0 ||
+                                ((JCMethodDecl) t).sym.name == names.init ||
+                                (((JCMethodDecl) t).mods.flags & (Flags.PRIVATE)) == 0 && ((JCMethodDecl) t).sym.packge().getQualifiedName() == names.java_lang)
+                                newdefs.append(t);
+                            break;
+                        case VARDEF:
+                            if (isInterface || (((JCVariableDecl) t).mods.flags & (Flags.PROTECTED|Flags.PUBLIC)) != 0 ||
+                                (((JCVariableDecl) t).mods.flags & (Flags.PRIVATE)) == 0 && ((JCVariableDecl) t).sym.packge().getQualifiedName() == names.java_lang)
+                                newdefs.append(t);
+                            break;
+                        default:
+                            break;
+                        }
+                    }
+                    tree.defs = newdefs.toList();
+                    super.visitClassDef(tree);
+                }
+            }
+            MethodBodyRemover r = new MethodBodyRemover();
+            return r.translate(cdef);
+        }
+
+    public void reportDeferredDiagnostics() {
+        if (errorCount() == 0
+                && annotationProcessingOccurred
+                && implicitSourceFilesRead
+                && implicitSourcePolicy == ImplicitSourcePolicy.UNSET) {
+            if (explicitAnnotationProcessingRequested())
+                log.warning(Warnings.ProcUseImplicit);
+            else
+                log.warning(Warnings.ProcUseProcOrImplicit);
+        }
+        chk.reportDeferredDiagnostics();
+        if (log.compressedOutput) {
+            log.mandatoryNote(null, Notes.CompressedDiags);
+        }
+    }
+
+    public void enterDone() {
+        enterDone = true;
+        annotate.enterDone();
+    }
+
+    public boolean isEnterDone() {
+        return enterDone;
+    }
+
+    private Name readModuleName(JavaFileObject fo) {
+        return parseAndGetName(fo, t -> {
+            JCModuleDecl md = t.getModuleDecl();
+
+            return md != null ? TreeInfo.fullName(md.getName()) : null;
+        });
+    }
+
+    private Name findPackageInFile(JavaFileObject fo) {
+        return parseAndGetName(fo, t -> t.getPackage() != null ?
+                                        TreeInfo.fullName(t.getPackage().getPackageName()) : null);
+    }
+
+    private Name parseAndGetName(JavaFileObject fo,
+                                 Function<JCTree.JCCompilationUnit, Name> tree2Name) {
+        DiagnosticHandler dh = new DiscardDiagnosticHandler(log);
+        try {
+            JCTree.JCCompilationUnit t = parse(fo, fo.getCharContent(false));
+            return tree2Name.apply(t);
+        } catch (IOException e) {
+            return null;
+        } finally {
+            log.popDiagnosticHandler(dh);
+        }
+    }
+
+    /** Close the compiler, flushing the logs
+     */
+    public void close() {
+        rootClasses = null;
+        finder = null;
+        reader = null;
+        make = null;
+        writer = null;
+        enter = null;
+        if (todo != null)
+            todo.clear();
+        todo = null;
+        parserFactory = null;
+        syms = null;
+        source = null;
+        attr = null;
+        chk = null;
+        gen = null;
+        flow = null;
+        transTypes = null;
+        lower = null;
+        annotate = null;
+        types = null;
+
+        log.flush();
+        try {
+            fileManager.flush();
+        } catch (IOException e) {
+            throw new Abort(e);
+        } finally {
+            if (names != null)
+                names.dispose();
+            names = null;
+
+            for (Closeable c: closeables) {
+                try {
+                    c.close();
+                } catch (IOException e) {
+                    // When javac uses JDK 7 as a baseline, this code would be
+                    // better written to set any/all exceptions from all the
+                    // Closeables as suppressed exceptions on the FatalError
+                    // that is thrown.
+                    JCDiagnostic msg = diagFactory.fragment(Fragments.FatalErrCantClose);
+                    throw new FatalError(msg, e);
+                }
+            }
+            closeables = List.nil();
+        }
+    }
+
+    protected void printNote(String lines) {
+        log.printRawLines(Log.WriterKind.NOTICE, lines);
+    }
+
+    /** Print numbers of errors and warnings.
+     */
+    public void printCount(String kind, int count) {
+        if (count != 0) {
+            String key;
+            if (count == 1)
+                key = "count." + kind;
+            else
+                key = "count." + kind + ".plural";
+            log.printLines(WriterKind.ERROR, key, String.valueOf(count));
+            log.flush(Log.WriterKind.ERROR);
+        }
+    }
+
+    private static long now() {
+        return System.currentTimeMillis();
+    }
+
+    private static long elapsed(long then) {
+        return now() - then;
+    }
+
+    public void newRound() {
+        inputFiles.clear();
+        todo.clear();
+    }
+}