changeset 1529:c924291865e5

8007034: debug printer for javac internals Reviewed-by: mcimadamore
author jjg
date Wed, 30 Jan 2013 09:47:12 -0800
parents 950d8195a5a4
children 8e4c22acebeb b7cb3d7ade25
files test/tools/javac/lib/DPrinter.java
diffstat 1 files changed, 1326 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/tools/javac/lib/DPrinter.java	Wed Jan 30 09:47:12 2013 -0800
@@ -0,0 +1,1326 @@
+/*
+ * Copyright (c) 2013, 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.
+ *
+ * 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.
+ */
+
+import java.io.File;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.EnumSet;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
+
+import javax.lang.model.element.Name;
+import javax.lang.model.element.TypeElement;
+import javax.tools.FileObject;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaFileObject;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.StandardLocation;
+import javax.tools.ToolProvider;
+
+import com.sun.source.util.JavacTask;
+import com.sun.source.util.TaskEvent;
+import com.sun.source.util.TaskListener;
+import com.sun.source.util.Trees;
+import com.sun.tools.javac.api.JavacTrees;
+import com.sun.tools.javac.code.Annotations;
+import com.sun.tools.javac.code.Attribute;
+import com.sun.tools.javac.code.Flags;
+import com.sun.tools.javac.code.Kinds;
+import com.sun.tools.javac.code.Printer;
+import com.sun.tools.javac.code.Scope;
+import com.sun.tools.javac.code.Scope.CompoundScope;
+import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.code.Symbol.*;
+import com.sun.tools.javac.code.Type;
+import com.sun.tools.javac.code.Type.*;
+import com.sun.tools.javac.code.TypeTag;
+import com.sun.tools.javac.tree.JCTree;
+import com.sun.tools.javac.tree.JCTree.*;
+import com.sun.tools.javac.tree.Pretty;
+import com.sun.tools.javac.tree.TreeInfo;
+import com.sun.tools.javac.tree.TreeScanner;
+import com.sun.tools.javac.util.Assert;
+import com.sun.tools.javac.util.Context;
+import com.sun.tools.javac.util.Log;
+
+
+/**
+ * Debug printer for javac internals, for when toString() just isn't enough.
+ *
+ * <p>
+ * The printer provides an API to generate structured views of javac objects,
+ * such as AST nodes, symbol, types and annotations. Various aspects of the
+ * output can be configured, such as whether to show nulls, empty lists, or
+ * a compressed representation of the source code. Visitors are used to walk
+ * object hierarchies, and can be replaced with custom visitors if the default
+ * visitors are not flexible enough.
+ *
+ * <p>
+ * In general, nodes are printed with an initial line identifying the node
+ * followed by indented lines for the child nodes. Currently, graphs are
+ * represented by printing a spanning subtree.
+ *
+ * <p>
+ * The printer can be accessed via a simple command-line utility,
+ * which makes it easy to see the internal representation of source code,
+ * such as simple test programs, during the compilation pipeline.
+ *
+ *  <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 DPrinter {
+    protected final PrintWriter out;
+    protected final Trees trees;
+    protected Printer printer;
+    protected boolean showEmptyItems = true;
+    protected boolean showNulls = true;
+    protected boolean showPositions = false;
+    protected boolean showSrc;
+    protected boolean showTreeSymbols;
+    protected boolean showTreeTypes;
+    protected int maxSrcLength = 32;
+    protected Locale locale = Locale.getDefault();
+    protected static final String NULL = "#null";
+
+    // <editor-fold defaultstate="collapsed" desc="Configuration">
+
+    public static DPrinter instance(Context context) {
+        DPrinter dp = context.get(DPrinter.class);
+        if (dp == null) {
+            dp = new DPrinter(context);
+        }
+        return dp;
+
+    }
+
+    protected DPrinter(Context context) {
+        context.put(DPrinter.class, this);
+        out = context.get(Log.outKey);
+        trees = JavacTrees.instance(context);
+    }
+
+    public DPrinter(PrintWriter out, Trees trees) {
+        this.out = out;
+        this.trees = trees;
+    }
+
+    public DPrinter emptyItems(boolean showEmptyItems) {
+        this.showEmptyItems = showEmptyItems;
+        return this;
+    }
+
+    public DPrinter nulls(boolean showNulls) {
+        this.showNulls = showNulls;
+        return this;
+    }
+
+    public DPrinter positions(boolean showPositions) {
+        this.showPositions = showPositions;
+        return this;
+    }
+
+    public DPrinter source(boolean showSrc) {
+        this.showSrc = showSrc;
+        return this;
+    }
+
+    public DPrinter source(int maxSrcLength) {
+        this.showSrc = true;
+        this.maxSrcLength = maxSrcLength;
+        return this;
+    }
+
+    public DPrinter treeSymbols(boolean showTreeSymbols) {
+        this.showTreeSymbols = showTreeSymbols;
+        return this;
+    }
+
+    public DPrinter treeTypes(boolean showTreeTypes) {
+        this.showTreeTypes = showTreeTypes;
+        return this;
+    }
+
+    public DPrinter typeSymbolPrinter(Printer p) {
+        printer = p;
+        return this;
+    }
+
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="Printing">
+
+    protected enum Details {
+        /** A one-line non-recursive summary */
+        SUMMARY,
+        /** Multi-line, possibly recursive. */
+        FULL
+    };
+
+    public void printAnnotations(String label, Annotations annotations) {
+        printAnnotations(label, annotations, Details.FULL);
+    }
+
+    protected void printAnnotations(String label, Annotations annotations, Details details) {
+        if (annotations == null) {
+            printNull(label);
+        } else {
+            // no SUMMARY format currently available to use
+
+            // use reflection to get at private fields
+            Object DECL_NOT_STARTED = getField(null, Annotations.class, "DECL_NOT_STARTED");
+            Object DECL_IN_PROGRESS = getField(null, Annotations.class, "DECL_IN_PROGRESS");
+            Object attributes = getField(annotations, Annotations.class, "attributes");
+            Object type_attributes = getField(annotations, Annotations.class, "type_attributes");
+
+            if (!showEmptyItems) {
+                if (attributes instanceof List && ((List) attributes).isEmpty()
+                        && attributes != DECL_NOT_STARTED
+                        && attributes != DECL_IN_PROGRESS
+                        && type_attributes instanceof List && ((List) type_attributes).isEmpty())
+                    return;
+            }
+
+            printString(label, "");
+
+            indent(+1);
+            if (attributes == DECL_NOT_STARTED)
+                printString("attributes", "DECL_NOT_STARTED");
+            else if (attributes == DECL_IN_PROGRESS)
+                printString("attributes", "DECL_IN_PROGRESS");
+            else if (attributes instanceof List)
+                printList("attributes", (List) attributes);
+            else
+                printObject("attributes", attributes, Details.SUMMARY);
+
+            if (attributes instanceof List)
+                printList("type_attributes", (List) type_attributes);
+            else
+                printObject("type_attributes", type_attributes, Details.SUMMARY);
+            indent(-1);
+        }
+    }
+
+    public void printAttribute(String label, Attribute attr) {
+        if (attr == null) {
+            printNull(label);
+        } else {
+            printString(label, attr.getClass().getSimpleName());
+
+            indent(+1);
+            attr.accept(attrVisitor);
+            indent(-1);
+        }
+    }
+
+    public void printFileObject(String label, FileObject fo) {
+        if (fo == null) {
+            printNull(label);
+        } else {
+            printString(label, fo.getName());
+        }
+    }
+
+    protected <T> void printImplClass(T item, Class<? extends T> stdImplClass) {
+        if (item.getClass() != stdImplClass)
+            printString("impl", item.getClass().getName());
+    }
+
+    public void printInt(String label, int i) {
+        printString(label, String.valueOf(i));
+    }
+
+    public void printList(String label, List<?> list) {
+        if (list == null) {
+             printNull(label);
+        } else if (!list.isEmpty() || showEmptyItems) {
+            printString(label, "[" + list.size() + "]");
+
+            indent(+1);
+            int i = 0;
+            for (Object item: list) {
+                printObject(String.valueOf(i++), item, Details.FULL);
+            }
+            indent(-1);
+        }
+    }
+
+    public void printName(String label, Name name) {
+        if (name == null) {
+            printNull(label);
+        } else {
+            printString(label, name.toString());
+        }
+    }
+
+    public void printNull(String label) {
+        if (showNulls)
+            printString(label, NULL);
+    }
+
+    protected void printObject(String label, Object item, Details details) {
+        if (item == null) {
+            printNull(label);
+        } else if (item instanceof Attribute) {
+            printAttribute(label, (Attribute) item);
+        } else if (item instanceof Symbol) {
+            printSymbol(label, (Symbol) item, details);
+        } else if (item instanceof Type) {
+            printType(label, (Type) item, details);
+        } else if (item instanceof JCTree) {
+            printTree(label, (JCTree) item);
+        } else if (item instanceof List) {
+            printList(label, (List) item);
+        } else if (item instanceof Name) {
+            printName(label, (Name) item);
+        } else {
+            printString(label, String.valueOf(item));
+        }
+    }
+
+    public void printScope(String label, Scope scope) {
+        printScope(label, scope, Details.FULL);
+    }
+
+    public void printScope(String label, Scope scope, Details details) {
+        if (scope == null) {
+            printNull(label);
+        } else {
+            switch (details) {
+                case SUMMARY: {
+                    indent();
+                    out.print(label);
+                    out.print(": [");
+                    String sep = "";
+                    for (Symbol sym: scope.getElements()) {
+                        out.print(sep);
+                        out.print(sym.name);
+                        sep = ",";
+                    }
+                    out.println("]");
+                    break;
+                }
+
+                case FULL: {
+                    indent();
+                    out.println(label);
+
+                    indent(+1);
+                    printImplClass(scope, Scope.class);
+                    printSymbol("owner", scope.owner, Details.SUMMARY);
+                    printScope("next", scope.next, Details.SUMMARY);
+                    printObject("shared", getField(scope, Scope.class, "shared"), Details.SUMMARY);
+                    if (scope instanceof CompoundScope) {
+                        printObject("subScopes",
+                                getField(scope, CompoundScope.class, "subScopes"),
+                                Details.FULL);
+                    } else {
+                        for (Symbol sym : scope.getElements()) {
+                            printSymbol(sym.name.toString(), sym, Details.SUMMARY);
+                        }
+                    }
+                    indent(-1);
+                    break;
+                }
+            }
+        }
+    }
+
+    public void printSource(String label, JCTree tree) {
+        printString(label, Pretty.toSimpleString(tree, maxSrcLength));
+    }
+
+    public void printString(String label, String text) {
+        indent();
+        out.print(label);
+        out.print(": ");
+        out.print(text);
+        out.println();
+    }
+
+    public void printSymbol(String label, Symbol symbol) {
+        printSymbol(label, symbol, Details.FULL);
+    }
+
+    protected void printSymbol(String label, Symbol sym, Details details) {
+        if (sym == null) {
+            printNull(label);
+        } else {
+            switch (details) {
+            case SUMMARY:
+                printString(label, toString(sym));
+                break;
+
+            case FULL:
+                indent();
+                out.print(label);
+                out.println(": " + String.format("0x%x", sym.kind)
+                        + "--" + Kinds.kindName(sym).name()
+                        + " " + sym.getKind()
+                        + " " + sym.name
+                        + " " + String.format("#%x", sym.hashCode()));
+
+                indent(+1);
+                if (showSrc) {
+                    JCTree tree = (JCTree) trees.getTree(sym);
+                    if (tree != null)
+                        printSource("src", tree);
+                }
+                printString("flags", String.format("0x%x--%s",
+                        sym.flags_field, Flags.toString(sym.flags_field)));
+                printObject("completer", sym.completer, Details.SUMMARY); // what if too long?
+                printSymbol("owner", sym.owner, Details.SUMMARY);
+                printType("type", sym.type, Details.SUMMARY);
+                printType("erasure", sym.erasure_field, Details.SUMMARY);
+                sym.accept(symVisitor, true);
+                printAnnotations("annotations", sym.annotations, Details.SUMMARY);
+                indent(-1);
+            }
+        }
+    }
+
+    protected String toString(Symbol sym) {
+        return (printer != null) ? printer.visit(sym, locale) : String.valueOf(sym);
+    }
+
+    protected void printTree(String label, JCTree tree) {
+        if (tree == null) {
+            printNull(label);
+        } else {
+            indent();
+            out.print(label + ": " + tree.getTag());
+            if (showPositions) {
+                // We can always get start position, but to get end position
+                // and/or line+offset, we would need a JCCompilationUnit
+                out.print(" pos:" + tree.pos);
+            }
+            if (showTreeTypes && tree.type != null)
+                out.print(" type:" + toString(tree.type));
+            Symbol sym;
+            if (showTreeSymbols && (sym = TreeInfo.symbolFor(tree)) != null)
+                out.print(" sym:" + toString(sym));
+            out.println();
+
+            indent(+1);
+            if (showSrc) {
+                indent();
+                out.println("src: " + Pretty.toSimpleString(tree, maxSrcLength));
+            }
+            tree.accept(treeVisitor);
+            indent(-1);
+        }
+    }
+
+    public void printType(String label, Type type) {
+        printType(label, type, Details.FULL);
+    }
+
+    protected void printType(String label, Type type, Details details) {
+        if (type == null)
+            printNull(label);
+        else {
+            switch (details) {
+                case SUMMARY:
+                    printString(label, toString(type));
+                    break;
+
+                case FULL:
+                    indent();
+                    out.print(label);
+                    out.println(": " + type.getTag()
+                            + " " + String.format("#%x", type.hashCode()));
+
+                    indent(+1);
+                    printSymbol("tsym", type.tsym, Details.SUMMARY);
+                    printObject("constValue", type.constValue(), Details.SUMMARY);
+                    type.accept(typeVisitor, true);
+                    indent(-1);
+            }
+        }
+    }
+
+    protected String toString(Type type) {
+        return (printer != null) ? printer.visit(type, locale) : String.valueOf(type);
+    }
+
+    private int indent = 0;
+
+    protected void indent() {
+        for (int i = 0; i < indent; i++) {
+            out.print("  ");
+        }
+    }
+
+    protected void indent(int n) {
+        indent += n;
+    }
+
+    protected Object getField(Object o, Class<?> clazz, String name) {
+        try {
+            Field f = clazz.getDeclaredField(name);
+            boolean prev = f.isAccessible();
+            f.setAccessible(true);
+            try {
+                return f.get(o);
+            } finally {
+                f.setAccessible(prev);
+            }
+        } catch (ReflectiveOperationException e) {
+            return e;
+        } catch (SecurityException e) {
+            return e;
+        }
+    }
+
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="JCTree visitor methods">
+
+    protected JCTree.Visitor treeVisitor = new TreeVisitor();
+
+    /**
+     * Default visitor class for JCTree (AST) objects.
+     */
+    public class TreeVisitor extends JCTree.Visitor {
+        @Override
+        public void visitTopLevel(JCCompilationUnit tree) {
+            printList("packageAnnotations", tree.packageAnnotations);
+            printTree("pid", tree.pid);
+            printList("defs", tree.defs);
+        }
+
+        @Override
+        public void visitImport(JCImport tree) {
+            printTree("qualid", tree.qualid);
+        }
+
+        @Override
+        public void visitClassDef(JCClassDecl tree) {
+            printName("name", tree.name);
+            printTree("mods", tree.mods);
+            printList("typarams", tree.typarams);
+            printTree("extending", tree.extending);
+            printList("implementing", tree.implementing);
+            printList("defs", tree.defs);
+        }
+
+        @Override
+        public void visitMethodDef(JCMethodDecl tree) {
+            printName("name", tree.name);
+            printTree("mods", tree.mods);
+            printTree("restype", tree.restype);
+            printList("typarams", tree.typarams);
+            printTree("recvparam", tree.recvparam);
+            printList("params", tree.params);
+            printList("thrown", tree.thrown);
+            printTree("defaultValue", tree.defaultValue);
+            printTree("body", tree.body);
+        }
+
+        @Override
+        public void visitVarDef(JCVariableDecl tree) {
+            printName("name", tree.name);
+            printTree("mods", tree.mods);
+            printTree("vartype", tree.vartype);
+            printTree("init", tree.init);
+        }
+
+        @Override
+        public void visitSkip(JCSkip tree) {
+        }
+
+        @Override
+        public void visitBlock(JCBlock tree) {
+            printList("stats", tree.stats);
+        }
+
+        @Override
+        public void visitDoLoop(JCDoWhileLoop tree) {
+            printTree("body", tree.body);
+            printTree("cond", tree.cond);
+        }
+
+        @Override
+        public void visitWhileLoop(JCWhileLoop tree) {
+            printTree("cond", tree.cond);
+            printTree("body", tree.body);
+        }
+
+        @Override
+        public void visitForLoop(JCForLoop tree) {
+            printList("init", tree.init);
+            printTree("cond", tree.cond);
+            printList("step", tree.step);
+            printTree("body", tree.body);
+        }
+
+        @Override
+        public void visitForeachLoop(JCEnhancedForLoop tree) {
+            printTree("var", tree.var);
+            printTree("expr", tree.expr);
+            printTree("body", tree.body);
+        }
+
+        @Override
+        public void visitLabelled(JCLabeledStatement tree) {
+            printTree("body", tree.body);
+        }
+
+        @Override
+        public void visitSwitch(JCSwitch tree) {
+            printTree("selector", tree.selector);
+            printList("cases", tree.cases);
+        }
+
+        @Override
+        public void visitCase(JCCase tree) {
+            printTree("pat", tree.pat);
+            printList("stats", tree.stats);
+        }
+
+        @Override
+        public void visitSynchronized(JCSynchronized tree) {
+            printTree("lock", tree.lock);
+            printTree("body", tree.body);
+        }
+
+        @Override
+        public void visitTry(JCTry tree) {
+            printList("resources", tree.resources);
+            printTree("body", tree.body);
+            printList("catchers", tree.catchers);
+            printTree("finalizer", tree.finalizer);
+        }
+
+        @Override
+        public void visitCatch(JCCatch tree) {
+            printTree("param", tree.param);
+            printTree("body", tree.body);
+        }
+
+        @Override
+        public void visitConditional(JCConditional tree) {
+            printTree("cond", tree.cond);
+            printTree("truepart", tree.truepart);
+            printTree("falsepart", tree.falsepart);
+        }
+
+        @Override
+        public void visitIf(JCIf tree) {
+            printTree("cond", tree.cond);
+            printTree("thenpart", tree.thenpart);
+            printTree("elsepart", tree.elsepart);
+        }
+
+        @Override
+        public void visitExec(JCExpressionStatement tree) {
+            printTree("expr", tree.expr);
+        }
+
+        @Override
+        public void visitBreak(JCBreak tree) {
+            printName("label", tree.label);
+        }
+
+        @Override
+        public void visitContinue(JCContinue tree) {
+            printName("label", tree.label);
+        }
+
+        @Override
+        public void visitReturn(JCReturn tree) {
+            printTree("expr", tree.expr);
+        }
+
+        @Override
+        public void visitThrow(JCThrow tree) {
+            printTree("expr", tree.expr);
+        }
+
+        @Override
+        public void visitAssert(JCAssert tree) {
+            printTree("cond", tree.cond);
+            printTree("detail", tree.detail);
+        }
+
+        @Override
+        public void visitApply(JCMethodInvocation tree) {
+            printList("typeargs", tree.typeargs);
+            printTree("meth", tree.meth);
+            printList("args", tree.args);
+        }
+
+        @Override
+        public void visitNewClass(JCNewClass tree) {
+            printTree("encl", tree.encl);
+            printList("typeargs", tree.typeargs);
+            printTree("clazz", tree.clazz);
+            printList("args", tree.args);
+            printTree("def", tree.def);
+        }
+
+        @Override
+        public void visitNewArray(JCNewArray tree) {
+            printList("annotations", tree.annotations);
+            printTree("elemtype", tree.elemtype);
+            printList("dims", tree.dims);
+            printList("dimAnnotations", tree.dimAnnotations);
+            printList("elems", tree.elems);
+        }
+
+        @Override
+        public void visitLambda(JCLambda tree) {
+            printTree("body", tree.body);
+            printList("params", tree.params);
+        }
+
+        @Override
+        public void visitParens(JCParens tree) {
+            printTree("expr", tree.expr);
+        }
+
+        @Override
+        public void visitAssign(JCAssign tree) {
+            printTree("lhs", tree.lhs);
+            printTree("rhs", tree.rhs);
+        }
+
+        @Override
+        public void visitAssignop(JCAssignOp tree) {
+            printTree("lhs", tree.lhs);
+            printTree("rhs", tree.rhs);
+        }
+
+        @Override
+        public void visitUnary(JCUnary tree) {
+            printTree("arg", tree.arg);
+        }
+
+        @Override
+        public void visitBinary(JCBinary tree) {
+            printTree("lhs", tree.lhs);
+            printTree("rhs", tree.rhs);
+        }
+
+        @Override
+        public void visitTypeCast(JCTypeCast tree) {
+            printTree("clazz", tree.clazz);
+            printTree("expr", tree.expr);
+        }
+
+        @Override
+        public void visitTypeTest(JCInstanceOf tree) {
+            printTree("expr", tree.expr);
+            printTree("clazz", tree.clazz);
+        }
+
+        @Override
+        public void visitIndexed(JCArrayAccess tree) {
+            printTree("indexed", tree.indexed);
+            printTree("index", tree.index);
+        }
+
+        @Override
+        public void visitSelect(JCFieldAccess tree) {
+            printTree("selected", tree.selected);
+        }
+
+        @Override
+        public void visitReference(JCMemberReference tree) {
+            printTree("expr", tree.expr);
+            printList("typeargs", tree.typeargs);
+        }
+
+        @Override
+        public void visitIdent(JCIdent tree) {
+            printName("name", tree.name);
+        }
+
+        @Override
+        public void visitLiteral(JCLiteral tree) {
+            printString("value", Pretty.toSimpleString(tree, 32));
+        }
+
+        @Override
+        public void visitTypeIdent(JCPrimitiveTypeTree tree) {
+            printString("typetag", tree.typetag.name());
+        }
+
+        @Override
+        public void visitTypeArray(JCArrayTypeTree tree) {
+            printTree("elemtype", tree.elemtype);
+        }
+
+        @Override
+        public void visitTypeApply(JCTypeApply tree) {
+            printTree("clazz", tree.clazz);
+            printList("arguments", tree.arguments);
+        }
+
+        @Override
+        public void visitTypeUnion(JCTypeUnion tree) {
+            printList("alternatives", tree.alternatives);
+        }
+
+        @Override
+        public void visitTypeIntersection(JCTypeIntersection tree) {
+            printList("bounds", tree.bounds);
+        }
+
+        @Override
+        public void visitTypeParameter(JCTypeParameter tree) {
+            printName("name", tree.name);
+            printList("annotations", tree.annotations);
+            printList("bounds", tree.bounds);
+        }
+
+        @Override
+        public void visitWildcard(JCWildcard tree) {
+            printTree("kind", tree.kind);
+            printTree("inner", tree.inner);
+        }
+
+        @Override
+        public void visitTypeBoundKind(TypeBoundKind tree) {
+            printString("kind", tree.kind.name());
+        }
+
+        @Override
+        public void visitModifiers(JCModifiers tree) {
+            printList("annotations", tree.annotations);
+            printString("flags", String.valueOf(Flags.asFlagSet(tree.flags)));
+        }
+
+        @Override
+        public void visitAnnotation(JCAnnotation tree) {
+            printTree("annotationType", tree.annotationType);
+            printList("args", tree.args);
+        }
+
+        @Override
+        public void visitAnnotatedType(JCAnnotatedType tree) {
+            printList("annotations", tree.annotations);
+            printTree("underlyingType", tree.underlyingType);
+        }
+
+        @Override
+        public void visitErroneous(JCErroneous tree) {
+            printList("errs", tree.errs);
+        }
+
+        @Override
+        public void visitLetExpr(LetExpr tree) {
+            printList("defs", tree.defs);
+            printTree("expr", tree.expr);
+        }
+
+        @Override
+        public void visitTree(JCTree tree) {
+            Assert.error();
+        }
+    }
+
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="Symbol visitor">
+
+    protected Symbol.Visitor<Void,Boolean> symVisitor = new SymbolVisitor();
+
+    /**
+     * Default visitor class for Symbol objects.
+     * Note: each visitXYZ method ends by calling the corresponding
+     * visit method for its superclass.
+     */
+    class SymbolVisitor implements Symbol.Visitor<Void,Boolean> {
+        @Override
+        public Void visitClassSymbol(ClassSymbol sym, Boolean impl) {
+            if (impl) printImplClass(sym, ClassSymbol.class);
+            printName("fullname", sym.fullname);
+            printName("flatname", sym.flatname);
+            printScope("members", sym.members_field);
+            printFileObject("sourcefile", sym.sourcefile);
+            printFileObject("classfile", sym.classfile);
+            // trans-local?
+            // pool?
+            return visitTypeSymbol(sym, false);
+        }
+
+        @Override
+        public Void visitMethodSymbol(MethodSymbol sym, Boolean impl) {
+            if (impl) printImplClass(sym, MethodSymbol.class);
+            // code
+            printList("params", sym.params);
+            printList("savedParameterNames", sym.savedParameterNames);
+            return visitSymbol(sym, false);
+        }
+
+        @Override
+        public Void visitPackageSymbol(PackageSymbol sym, Boolean impl) {
+            if (impl) printImplClass(sym, PackageSymbol.class);
+            printName("fullname", sym.fullname);
+            printScope("members", sym.members_field);
+            printSymbol("package-info", sym.package_info, Details.SUMMARY);
+            return visitTypeSymbol(sym, false);
+        }
+
+        @Override
+        public Void visitOperatorSymbol(OperatorSymbol sym, Boolean impl) {
+            if (impl) printImplClass(sym, OperatorSymbol.class);
+            printInt("opcode", sym.opcode);
+            return visitMethodSymbol(sym, false);
+        }
+
+        @Override
+        public Void visitVarSymbol(VarSymbol sym, Boolean impl) {
+            if (impl) printImplClass(sym, VarSymbol.class);
+            printInt("pos", sym.pos);
+            printInt("adm", sym.adr);
+            // data is a private field, and the standard accessors may
+            // mutate it as part of lazy evaluation. Therefore, use
+            // reflection to get the raw data.
+            printObject("data", getField(sym, VarSymbol.class, "data"), Details.SUMMARY);
+            return visitSymbol(sym, false);
+        }
+
+        @Override
+        public Void visitTypeSymbol(TypeSymbol sym, Boolean impl) {
+            if (impl) printImplClass(sym, TypeSymbol.class);
+            return visitSymbol(sym, false);
+        }
+
+        @Override
+        public Void visitSymbol(Symbol sym, Boolean impl) {
+            if (impl) printImplClass(sym, Symbol.class);
+            return null;
+        }
+    }
+
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="Type visitor">
+
+    protected Type.Visitor<Void,Boolean> typeVisitor = new TypeVisitor();
+
+    /**
+     * Default visitor class for Type objects.
+     * Note: each visitXYZ method ends by calling the corresponding
+     * visit method for its superclass.
+     */
+    public class TypeVisitor implements Type.Visitor<Void,Boolean> {
+        public Void visitAnnotatedType(AnnotatedType type, Boolean impl) {
+            if (impl) printImplClass(type, AnnotatedType.class);
+            printList("typeAnnotations", type.typeAnnotations);
+            printType("underlyingType", type.underlyingType, Details.FULL);
+            return visitType(type, false);
+        }
+
+        public Void visitArrayType(ArrayType type, Boolean impl) {
+            if (impl) printImplClass(type, ArrayType.class);
+            printType("elemType", type.elemtype, Details.FULL);
+            return visitType(type, false);
+        }
+
+        public Void visitCapturedType(CapturedType type, Boolean impl) {
+            if (impl) printImplClass(type, CapturedType.class);
+            printType("wildcard", type.wildcard, Details.FULL);
+            return visitTypeVar(type, false);
+        }
+
+        public Void visitClassType(ClassType type, Boolean impl) {
+            if (impl) printImplClass(type, ClassType.class);
+            printType("outer", type.getEnclosingType(), Details.SUMMARY);
+            printList("typarams", type.typarams_field);
+            printList("allparams", type.allparams_field);
+            printType("supertype", type.supertype_field, Details.SUMMARY);
+            printList("interfaces", type.interfaces_field);
+            printList("allinterfaces", type.all_interfaces_field);
+            return visitType(type, false);
+        }
+
+        public Void visitErrorType(ErrorType type, Boolean impl) {
+            if (impl) printImplClass(type, ErrorType.class);
+            printType("originalType", type.getOriginalType(), Details.FULL);
+            return visitClassType(type, false);
+        }
+
+        public Void visitForAll(ForAll type, Boolean impl) {
+            if (impl) printImplClass(type, ForAll.class);
+            printList("tvars", type.tvars);
+            return visitDelegatedType(type);
+        }
+
+        public Void visitMethodType(MethodType type, Boolean impl) {
+            if (impl) printImplClass(type, MethodType.class);
+            printList("argtypes", type.argtypes);
+            printType("restype", type.restype, Details.FULL);
+            printList("thrown", type.thrown);
+            return visitType(type, false);
+        }
+
+        public Void visitPackageType(PackageType type, Boolean impl) {
+            if (impl) printImplClass(type, PackageType.class);
+            return visitType(type, false);
+        }
+
+        public Void visitTypeVar(TypeVar type, Boolean impl) {
+            if (impl) printImplClass(type, TypeVar.class);
+            // For TypeVars (and not subtypes), the bound should always be
+            // null or bot. So, only print the bound for subtypes of TypeVar,
+            // or if the bound is (erroneously) not null or bot.
+            if (!type.hasTag(TypeTag.TYPEVAR)
+                    || !(type.bound == null || type.bound.hasTag(TypeTag.BOT))) {
+                printType("bound", type.bound, Details.FULL);
+            }
+            printType("lower", type.lower, Details.FULL);
+            return visitType(type, false);
+        }
+
+        public Void visitUndetVar(UndetVar type, Boolean impl) {
+            if (impl) printImplClass(type, UndetVar.class);
+            for (UndetVar.InferenceBound ib: UndetVar.InferenceBound.values())
+                printList("bounds." + ib, type.getBounds(ib));
+            printType("inst", type.inst, Details.SUMMARY);
+            return visitDelegatedType(type);
+        }
+
+        public Void visitWildcardType(WildcardType type, Boolean impl) {
+            if (impl) printImplClass(type, WildcardType.class);
+            printType("type", type.type, Details.SUMMARY);
+            printString("kind", type.kind.name());
+            printType("bound", type.bound, Details.SUMMARY);
+            return visitType(type, false);
+        }
+
+        protected Void visitDelegatedType(DelegatedType type) {
+            printType("qtype", type.qtype, Details.FULL);
+            return visitType(type, false);
+        }
+
+        public Void visitType(Type type, Boolean impl) {
+            if (impl) printImplClass(type, Type.class);
+            return null;
+        }
+    }
+
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="Attribute (annotations) visitor">
+
+    protected Attribute.Visitor attrVisitor = new AttributeVisitor();
+
+    /**
+     * Default visitor class for Attribute (annotation) objects.
+     */
+    public class AttributeVisitor implements Attribute.Visitor {
+
+        public void visitConstant(Attribute.Constant a) {
+            printObject("value", a.value, Details.SUMMARY);
+            visitAttribute(a);
+        }
+
+        public void visitClass(Attribute.Class a) {
+            printObject("classType", a.classType, Details.SUMMARY);
+            visitAttribute(a);
+        }
+
+        public void visitCompound(Attribute.Compound a) {
+            if (a instanceof Attribute.TypeCompound) {
+                Attribute.TypeCompound ta = (Attribute.TypeCompound) a;
+                // consider a custom printer?
+                printObject("position", ta.position, Details.SUMMARY);
+            }
+            printObject("synthesized", a.isSynthesized(), Details.SUMMARY);
+            printList("values", a.values);
+            visitAttribute(a);
+        }
+
+        public void visitArray(Attribute.Array a) {
+            printList("values", Arrays.asList(a.values));
+            visitAttribute(a);
+        }
+
+        public void visitEnum(Attribute.Enum a) {
+            printSymbol("value", a.value, Details.SUMMARY);
+            visitAttribute(a);
+        }
+
+        public void visitError(Attribute.Error a) {
+            visitAttribute(a);
+        }
+
+        public void visitAttribute(Attribute a) {
+            printType("type", a.type, Details.SUMMARY);
+        }
+
+    }
+    // </editor-fold>
+
+    // <editor-fold defaultstate="collapsed" desc="Utility front end">
+
+    /**
+     * Utility class to invoke DPrinter from the command line.
+     */
+    static class Main {
+        public static void main(String... args) throws IOException {
+            PrintWriter out = new PrintWriter(System.out);
+            try {
+                if (args.length == 0)
+                    usage(out);
+                else
+                    new Main().run(out, args);
+            } finally {
+                out.flush();
+            }
+        }
+
+        static void usage(PrintWriter out) {
+            out.println("Usage:");
+            out.println("  java " + Main.class.getName() + " mode [options] [javac-options]");
+            out.println("where options include:");
+            out.println("  -before PARSE|ENTER|ANALYZE|GENERATE|ANNOTATION_PROCESSING|ANNOTATION_PROCESSING_ROUND");
+            out.println("  -after PARSE|ENTER|ANALYZE|GENERATE|ANNOTATION_PROCESSING|ANNOTATION_PROCESSING_ROUND");
+            out.println("  -showPositions");
+            out.println("  -showSource");
+            out.println("  -showTreeSymbols");
+            out.println("  -showTreeTypes");
+            out.println("  -hideEmptyItems");
+            out.println("  -hideNulls");
+        }
+
+        void run(PrintWriter out, String... args) throws IOException {
+            JavaCompiler c = ToolProvider.getSystemJavaCompiler();
+            StandardJavaFileManager fm = c.getStandardFileManager(null, null, null);
+
+            // DPrinter options
+            final Set<TaskEvent.Kind> before = EnumSet.noneOf(TaskEvent.Kind.class);
+            final Set<TaskEvent.Kind> after = EnumSet.noneOf(TaskEvent.Kind.class);
+            boolean showPositions = false;
+            boolean showSource = false;
+            boolean showTreeSymbols = false;
+            boolean showTreeTypes = false;
+            boolean showEmptyItems = true;
+            boolean showNulls = true;
+
+            // javac options
+            Collection<String> options = new ArrayList<String>();
+            Collection<File> files = new ArrayList<File>();
+            String classpath = null;
+            String classoutdir = null;
+
+            final Handler h = getHandlers().get(args[0]);
+            if (h == null)
+                throw new IllegalArgumentException(args[0]);
+
+            for (int i = 1; i < args.length; i++) {
+                String arg = args[i];
+                if (arg.equals("-before") && i + 1 < args.length) {
+                    before.add(getKind(args[++i]));
+                } else if (arg.equals("-after") && i + 1 < args.length) {
+                    after.add(getKind(args[++i]));
+                } else if (arg.equals("-showPositions")) {
+                    showPositions = true;
+                } else if (arg.equals("-showSource")) {
+                    showSource = true;
+                } else if (arg.equals("-showTreeSymbols")) {
+                    showTreeSymbols = true;
+                } else if (arg.equals("-showTreeTypes")) {
+                    showTreeTypes = true;
+                } else if (arg.equals("-hideEmptyLists")) {
+                    showEmptyItems = false;
+                } else if (arg.equals("-hideNulls")) {
+                    showNulls = false;
+                } else if (arg.equals("-classpath") && i + 1 < args.length) {
+                    classpath = args[++i];
+                } else if (arg.equals("-d") && i + 1 < args.length) {
+                    classoutdir = args[++i];
+                } else if (arg.startsWith("-")) {
+                    int n = c.isSupportedOption(arg);
+                    if (n < 0) throw new IllegalArgumentException(arg);
+                    options.add(arg);
+                    while (n > 0) options.add(args[++i]);
+                } else if (arg.endsWith(".java")) {
+                    files.add(new File(arg));
+                }
+            }
+
+            if (classoutdir != null) {
+                fm.setLocation(StandardLocation.CLASS_OUTPUT, Arrays.asList(new File(classoutdir)));
+            }
+
+            if (classpath != null) {
+                Collection<File> path = new ArrayList<File>();
+                for (String p: classpath.split(File.pathSeparator)) {
+                    if (p.isEmpty()) continue;
+                    File f = new File(p);
+                    if (f.exists()) path.add(f);
+                }
+                fm.setLocation(StandardLocation.CLASS_PATH, path);
+            }
+            Iterable<? extends JavaFileObject> fos = fm.getJavaFileObjectsFromFiles(files);
+
+            JavacTask task = (JavacTask) c.getTask(out, fm, null, options, null, fos);
+            final Trees trees = Trees.instance(task);
+
+            final DPrinter dprinter = new DPrinter(out, trees);
+            dprinter.source(showSource)
+                    .emptyItems(showEmptyItems)
+                    .nulls(showNulls)
+                    .positions(showPositions)
+                    .treeSymbols(showTreeSymbols)
+                    .treeTypes(showTreeTypes);
+
+            if (before.isEmpty() && after.isEmpty()) {
+                if (h.name.equals("trees") && !showTreeSymbols && !showTreeTypes)
+                    after.add(TaskEvent.Kind.PARSE);
+                else
+                    after.add(TaskEvent.Kind.ANALYZE);
+            }
+
+            task.addTaskListener(new TaskListener() {
+                public void started(TaskEvent e) {
+                    if (before.contains(e.getKind()))
+                        handle(e);
+                }
+
+                public void finished(TaskEvent e) {
+                    if (after.contains(e.getKind()))
+                        handle(e);
+                }
+
+                private void handle(TaskEvent e) {
+                     switch (e.getKind()) {
+                         case PARSE:
+                         case ENTER:
+                             h.handle(e.getSourceFile().getName(),
+                                     (JCTree) e.getCompilationUnit(),
+                                     dprinter);
+                             break;
+
+                         default:
+                             TypeElement elem = e.getTypeElement();
+                             h.handle(elem.toString(),
+                                     (JCTree) trees.getTree(elem),
+                                     dprinter);
+                             break;
+                     }
+                }
+            });
+
+            task.call();
+        }
+
+        TaskEvent.Kind getKind(String s) {
+            return TaskEvent.Kind.valueOf(s.toUpperCase());
+        }
+
+        static protected abstract class Handler {
+            final String name;
+            Handler(String name) {
+                this.name = name;
+            }
+            abstract void handle(String label, JCTree tree, DPrinter dprinter);
+        }
+
+        Map<String,Handler> getHandlers() {
+            Map<String,Handler> map = new HashMap<String, Handler>();
+            for (Handler h: defaultHandlers) {
+                map.put(h.name, h);
+            }
+            return map;
+        }
+
+        protected final Handler[] defaultHandlers = {
+            new Handler("trees") {
+                @Override
+                void handle(String name, JCTree tree, DPrinter dprinter) {
+                    dprinter.printTree(name, tree);
+                    dprinter.out.println();
+                }
+            },
+
+            new Handler("symbols") {
+                @Override
+                void handle(String name, JCTree tree, final DPrinter dprinter) {
+                    TreeScanner ds = new TreeScanner() {
+                        @Override
+                        public void visitClassDef(JCClassDecl tree) {
+                            visitDecl(tree, tree.sym);
+                            super.visitClassDef(tree);
+                        }
+
+                        @Override
+                        public void visitMethodDef(JCMethodDecl tree) {
+                            visitDecl(tree, tree.sym);
+                            super.visitMethodDef(tree);
+                        }
+
+                        @Override
+                        public void visitVarDef(JCVariableDecl tree) {
+                            visitDecl(tree, tree.sym);
+                            super.visitVarDef(tree);
+                        }
+
+                        void visitDecl(JCTree tree, Symbol sym) {
+                            dprinter.printSymbol(sym.name.toString(), sym);
+                            dprinter.out.println();
+                        }
+                    };
+                    ds.scan(tree);
+                }
+            },
+
+            new Handler("types") {
+                @Override
+                void handle(String name, JCTree tree, final DPrinter dprinter) {
+                    TreeScanner ts = new TreeScanner() {
+                        @Override
+                        public void scan(JCTree tree) {
+                            if (tree == null) {
+                                return;
+                            }
+                            if (tree.type != null) {
+                                String label = Pretty.toSimpleString(tree);
+                                dprinter.printType(label, tree.type);
+                                dprinter.out.println();
+                            }
+                            super.scan(tree);
+                        }
+                    };
+                    ts.scan(tree);
+                }
+            }
+        };
+    }
+
+    // </editor-fold>
+
+}