changeset 25844:48eab270456c

8048890: Add option to keep track of symbol completion dependencies Summary: Generate dot file with representation of javac on-demand symbol completion dependencies Reviewed-by: jjg, jlahoda
author mcimadamore
date Thu, 24 Jul 2014 13:11:03 +0100
parents 7ca97d2d0405
children 14935053bb07
files langtools/src/share/classes/com/sun/tools/javac/code/ClassFinder.java langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java langtools/src/share/classes/com/sun/tools/javac/comp/MemberEnter.java langtools/src/share/classes/com/sun/tools/javac/main/Main.java langtools/src/share/classes/com/sun/tools/javac/util/Dependencies.java langtools/src/share/classes/com/sun/tools/javac/util/GraphUtils.java
diffstat 7 files changed, 778 insertions(+), 110 deletions(-) [+]
line wrap: on
line diff
--- a/langtools/src/share/classes/com/sun/tools/javac/code/ClassFinder.java	Wed Jul 23 09:19:23 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/code/ClassFinder.java	Thu Jul 24 13:11:03 2014 +0100
@@ -103,6 +103,10 @@
      */
     private final JavaFileManager fileManager;
 
+    /** Dependency tracker
+     */
+    private final Dependencies dependencies;
+
     /** Factory for diagnostics
      */
     JCDiagnostic.Factory diagFactory;
@@ -150,6 +154,7 @@
         names = Names.instance(context);
         syms = Symtab.instance(context);
         fileManager = context.get(JavaFileManager.class);
+        dependencies = Dependencies.instance(context);
         if (fileManager == null)
             throw new AssertionError("FileManager initialization error");
         diagFactory = JCDiagnostic.Factory.instance(context);
@@ -179,18 +184,23 @@
      */
     private void complete(Symbol sym) throws CompletionFailure {
         if (sym.kind == TYP) {
-            ClassSymbol c = (ClassSymbol)sym;
-            c.members_field = new Scope.ErrorScope(c); // make sure it's always defined
-            annotate.enterStart();
             try {
-                completeOwners(c.owner);
-                completeEnclosing(c);
+                ClassSymbol c = (ClassSymbol) sym;
+                dependencies.push(c);
+                c.members_field = new Scope.ErrorScope(c); // make sure it's always defined
+                annotate.enterStart();
+                try {
+                    completeOwners(c.owner);
+                    completeEnclosing(c);
+                } finally {
+                    // The flush needs to happen only after annotations
+                    // are filled in.
+                    annotate.enterDoneWithoutFlush();
+                }
+                fillIn(c);
             } finally {
-                // The flush needs to happen only after annotations
-                // are filled in.
-                annotate.enterDoneWithoutFlush();
+                dependencies.pop();
             }
-            fillIn(c);
         } else if (sym.kind == PCK) {
             PackageSymbol p = (PackageSymbol)sym;
             try {
@@ -257,7 +267,6 @@
                                                         + classfile.toUri());
                     }
                 }
-                return;
             } finally {
                 currentClassFile = previousClassFile;
             }
--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java	Wed Jul 23 09:19:23 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Attr.java	Thu Jul 24 13:11:03 2014 +0100
@@ -49,6 +49,7 @@
 import com.sun.tools.javac.tree.JCTree.*;
 import com.sun.tools.javac.tree.JCTree.JCPolyExpression.*;
 import com.sun.tools.javac.util.*;
+import com.sun.tools.javac.util.Dependencies.AttributionKind;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
 import com.sun.tools.javac.util.List;
 import static com.sun.tools.javac.code.Flags.*;
@@ -94,6 +95,7 @@
     final Annotate annotate;
     final DeferredLintHandler deferredLintHandler;
     final TypeEnvs typeEnvs;
+    final Dependencies dependencies;
 
     public static Attr instance(Context context) {
         Attr instance = context.get(attrKey);
@@ -123,6 +125,7 @@
         annotate = Annotate.instance(context);
         deferredLintHandler = DeferredLintHandler.instance(context);
         typeEnvs = TypeEnvs.instance(context);
+        dependencies = Dependencies.instance(context);
 
         Options options = Options.instance(context);
 
@@ -695,6 +698,7 @@
      */
     void attribTypeVariables(List<JCTypeParameter> typarams, Env<AttrContext> env) {
         for (JCTypeParameter tvar : typarams) {
+            dependencies.push(AttributionKind.TVAR, tvar);
             TypeVar a = (TypeVar)tvar.type;
             a.tsym.flags_field |= UNATTRIBUTED;
             a.bound = Type.noType;
@@ -710,6 +714,7 @@
                 types.setBounds(a, List.of(syms.objectType));
             }
             a.tsym.flags_field &= ~UNATTRIBUTED;
+            dependencies.pop();
         }
         for (JCTypeParameter tvar : typarams) {
             chk.checkNonCyclic(tvar.pos(), (TypeVar)tvar.type);
--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java	Wed Jul 23 09:19:23 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Infer.java	Thu Jul 24 13:11:03 2014 +0100
@@ -29,6 +29,7 @@
 import com.sun.tools.javac.tree.JCTree.JCTypeCast;
 import com.sun.tools.javac.tree.TreeInfo;
 import com.sun.tools.javac.util.*;
+import com.sun.tools.javac.util.GraphUtils.DottableNode;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
 import com.sun.tools.javac.util.List;
 import com.sun.tools.javac.code.*;
@@ -40,9 +41,9 @@
 import com.sun.tools.javac.comp.Infer.GraphSolver.InferenceGraph.Node;
 import com.sun.tools.javac.comp.Resolve.InapplicableMethodException;
 import com.sun.tools.javac.comp.Resolve.VerboseResolutionMode;
-import com.sun.tools.javac.util.GraphUtils.TarjanNode;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.EnumMap;
 import java.util.EnumSet;
@@ -50,6 +51,7 @@
 import java.util.HashSet;
 import java.util.LinkedHashSet;
 import java.util.Map;
+import java.util.Properties;
 import java.util.Set;
 
 import static com.sun.tools.javac.code.TypeTag.*;
@@ -1607,11 +1609,6 @@
         private DependencyKind(String dotSyle) {
             this.dotSyle = dotSyle;
         }
-
-        @Override
-        public String getDotStyle() {
-            return dotSyle;
-        }
     }
 
     /**
@@ -1684,7 +1681,7 @@
              * updates on the structure of the graph this node belongs to (used to
              * keep dependencies in sync).
              */
-            class Node extends GraphUtils.TarjanNode<ListBuffer<Type>> {
+            class Node extends GraphUtils.TarjanNode<ListBuffer<Type>, Node> implements DottableNode<ListBuffer<Type>, Node> {
 
                 /** map listing all dependencies (grouped by kind) */
                 EnumMap<DependencyKind, Set<Node>> deps;
@@ -1699,33 +1696,12 @@
                     return DependencyKind.values();
                 }
 
-                @Override
-                public String getDependencyName(GraphUtils.Node<ListBuffer<Type>> to, GraphUtils.DependencyKind dk) {
-                    if (dk == DependencyKind.STUCK) return "";
-                    else {
-                        StringBuilder buf = new StringBuilder();
-                        String sep = "";
-                        for (Type from : data) {
-                            UndetVar uv = (UndetVar)inferenceContext.asUndetVar(from);
-                            for (Type bound : uv.getBounds(InferenceBound.values())) {
-                                if (bound.containsAny(List.from(to.data))) {
-                                    buf.append(sep);
-                                    buf.append(bound);
-                                    sep = ",";
-                                }
-                            }
-                        }
-                        return buf.toString();
-                    }
-                }
-
-                @Override
                 public Iterable<? extends Node> getAllDependencies() {
                     return getDependencies(DependencyKind.values());
                 }
 
                 @Override
-                public Iterable<? extends TarjanNode<ListBuffer<Type>>> getDependenciesByKind(GraphUtils.DependencyKind dk) {
+                public Collection<? extends Node> getDependenciesByKind(GraphUtils.DependencyKind dk) {
                     return getDependencies((DependencyKind)dk);
                 }
 
@@ -1855,6 +1831,36 @@
                         }
                     }
                 }
+
+                @Override
+                public Properties nodeAttributes() {
+                    Properties p = new Properties();
+                    p.put("label", toString());
+                    return p;
+                }
+
+                @Override
+                public Properties dependencyAttributes(Node sink, GraphUtils.DependencyKind dk) {
+                    Properties p = new Properties();
+                    p.put("style", ((DependencyKind)dk).dotSyle);
+                    if (dk == DependencyKind.STUCK) return p;
+                    else {
+                        StringBuilder buf = new StringBuilder();
+                        String sep = "";
+                        for (Type from : data) {
+                            UndetVar uv = (UndetVar)inferenceContext.asUndetVar(from);
+                            for (Type bound : uv.getBounds(InferenceBound.values())) {
+                                if (bound.containsAny(List.from(sink.data))) {
+                                    buf.append(sep);
+                                    buf.append(bound);
+                                    sep = ",";
+                                }
+                            }
+                        }
+                        p.put("label", buf.toString());
+                    }
+                    return p;
+                }
             }
 
             /** the nodes in the inference graph */
--- a/langtools/src/share/classes/com/sun/tools/javac/comp/MemberEnter.java	Wed Jul 23 09:19:23 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/MemberEnter.java	Thu Jul 24 13:11:03 2014 +0100
@@ -55,6 +55,7 @@
 import static com.sun.tools.javac.code.TypeTag.TYPEVAR;
 import static com.sun.tools.javac.tree.JCTree.Tag.*;
 
+import com.sun.tools.javac.util.Dependencies.AttributionKind;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;
 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;
 
@@ -90,6 +91,7 @@
     private final DeferredLintHandler deferredLintHandler;
     private final Lint lint;
     private final TypeEnvs typeEnvs;
+    private final Dependencies dependencies;
 
     public static MemberEnter instance(Context context) {
         MemberEnter instance = context.get(memberEnterKey);
@@ -116,6 +118,7 @@
         deferredLintHandler = DeferredLintHandler.instance(context);
         lint = Lint.instance(context);
         typeEnvs = TypeEnvs.instance(context);
+        dependencies = Dependencies.instance(context);
         allowTypeAnnos = source.allowTypeAnnotations();
     }
 
@@ -555,6 +558,7 @@
 
     // process the non-static imports and the static imports of types.
     public void visitImport(JCImport tree) {
+        dependencies.push(AttributionKind.IMPORT, tree);
         JCFieldAccess imp = (JCFieldAccess)tree.qualid;
         Name name = TreeInfo.name(imp);
 
@@ -581,6 +585,7 @@
                 importNamed(tree.pos(), c, env);
             }
         }
+        dependencies.pop();
     }
 
     public void visitMethodDef(JCMethodDecl tree) {
@@ -952,6 +957,8 @@
         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);
         DiagnosticPosition prevLintPos = deferredLintHandler.setPos(tree.pos());
         try {
+            dependencies.push(c);
+
             // Save class environment for later member enter (2) processing.
             halfcompleted.append(env);
 
@@ -990,16 +997,21 @@
             Type supertype;
 
             if (tree.extending != null) {
-                supertype = attr.attribBase(tree.extending, baseEnv,
-                                            true, false, true);
-                if (sym.isAnonymous()) {
-                    annotate.annotateAnonClassDefLater(tree.extending,
-                                                       tree.mods.annotations,
-                                                       baseEnv, sym, tree.pos(),
-                                                       annotate.extendsCreator);
-                } else {
-                    annotate.annotateTypeLater(tree.extending, baseEnv, sym,
-                                               tree.pos(), annotate.extendsCreator);
+                dependencies.push(AttributionKind.EXTENDS, tree.extending);
+                try {
+                    supertype = attr.attribBase(tree.extending, baseEnv,
+                            true, false, true);
+                    if (sym.isAnonymous()) {
+                        annotate.annotateAnonClassDefLater(tree.extending,
+                                tree.mods.annotations,
+                                baseEnv, sym, tree.pos(),
+                                annotate.extendsCreator);
+                    } else {
+                        annotate.annotateTypeLater(tree.extending, baseEnv, sym,
+                                tree.pos(), annotate.extendsCreator);
+                    }
+                } finally {
+                    dependencies.pop();
                 }
             } else {
                 supertype = ((tree.mods.flags & Flags.ENUM) != 0)
@@ -1018,29 +1030,34 @@
             List<JCExpression> interfaceTrees = tree.implementing;
             int i = 0;
             for (JCExpression iface : interfaceTrees) {
-                Type it = attr.attribBase(iface, baseEnv, false, true, true);
-                if (it.hasTag(CLASS)) {
-                    interfaces.append(it);
-                    if (all_interfaces != null) all_interfaces.append(it);
-                    chk.checkNotRepeated(iface.pos(), types.erasure(it), interfaceSet);
-                } else {
-                    if (all_interfaces == null)
-                        all_interfaces = new ListBuffer<Type>().appendList(interfaces);
-                    all_interfaces.append(modelMissingTypes(it, iface, true));
+                dependencies.push(AttributionKind.IMPLEMENTS, iface);
+                try {
+                    Type it = attr.attribBase(iface, baseEnv, false, true, true);
+                    if (it.hasTag(CLASS)) {
+                        interfaces.append(it);
+                        if (all_interfaces != null) all_interfaces.append(it);
+                        chk.checkNotRepeated(iface.pos(), types.erasure(it), interfaceSet);
+                    } else {
+                        if (all_interfaces == null)
+                            all_interfaces = new ListBuffer<Type>().appendList(interfaces);
+                        all_interfaces.append(modelMissingTypes(it, iface, true));
 
+                    }
+                    if (sym.isAnonymous()) {
+                        // Note: if an anonymous class ever has more than
+                        // one supertype for some reason, this will
+                        // incorrectly attach tree.mods.annotations to ALL
+                        // supertypes, not just the first.
+                        annotate.annotateAnonClassDefLater(iface, tree.mods.annotations,
+                                baseEnv, sym, tree.pos(),
+                                annotate.implementsCreator(i++));
+                    } else {
+                        annotate.annotateTypeLater(iface, baseEnv, sym, tree.pos(),
+                                annotate.implementsCreator(i++));
+                    }
+                } finally {
+                    dependencies.pop();
                 }
-                if (sym.isAnonymous()) {
-                    // Note: if an anonymous class ever has more than
-                    // one supertype for some reason, this will
-                    // incorrectly attach tree.mods.annotations to ALL
-                    // supertypes, not just the first.
-                    annotate.annotateAnonClassDefLater(iface, tree.mods.annotations,
-                                                       baseEnv, sym, tree.pos(),
-                                                       annotate.implementsCreator(i++));
-                } else {
-                    annotate.annotateTypeLater(iface, baseEnv, sym, tree.pos(),
-                                               annotate.implementsCreator(i++));
-            }
             }
 
             if ((c.flags_field & ANNOTATION) != 0) {
@@ -1157,6 +1174,7 @@
         } finally {
             deferredLintHandler.setPos(prevLintPos);
             log.useSource(prev);
+            dependencies.pop();
         }
 
         // Enter all member fields and methods of a set of half completed
--- a/langtools/src/share/classes/com/sun/tools/javac/main/Main.java	Wed Jul 23 09:19:23 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/main/Main.java	Thu Jul 24 13:11:03 2014 +0100
@@ -488,6 +488,10 @@
                 }
             }
 
+            if (options.isSet("completionDeps")) {
+                Dependencies.GraphDependencies.preRegister(context);
+            }
+
             comp = JavaCompiler.instance(context);
 
             // FIXME: this code will not be invoked if using JavacTask.parse/analyze/generate
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/util/Dependencies.java	Thu Jul 24 13:11:03 2014 +0100
@@ -0,0 +1,559 @@
+/*
+ * Copyright (c) 2014, 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.util;
+
+import com.sun.tools.javac.code.Symbol;
+import com.sun.tools.javac.code.Symbol.ClassSymbol;
+import com.sun.tools.javac.code.Symbol.Completer;
+import com.sun.tools.javac.code.Symbol.CompletionFailure;
+import com.sun.tools.javac.main.JavaCompiler;
+import com.sun.tools.javac.tree.JCTree;
+import com.sun.tools.javac.util.GraphUtils.DotVisitor;
+import com.sun.tools.javac.util.GraphUtils.NodeVisitor;
+
+import java.io.Closeable;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.EnumMap;
+import java.util.EnumSet;
+import java.util.HashSet;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+import java.util.Stack;
+
+import javax.tools.JavaFileObject;
+
+/**
+ *  This class is used to track dependencies in the javac symbol completion process.
+ *
+ *  <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 abstract class Dependencies {
+
+    protected static final Context.Key<Dependencies> dependenciesKey = new Context.Key<>();
+
+    public static Dependencies instance(Context context) {
+        Dependencies instance = context.get(dependenciesKey);
+        if (instance == null) {
+            //use a do-nothing implementation in case no other implementation has been set by preRegister
+            instance = new DummyDependencies(context);
+        }
+        return instance;
+    }
+
+    Dependencies(Context context) {
+        context.put(dependenciesKey, this);
+    }
+
+    /**
+     * This enum models different kinds of attribution actions triggered during
+     * symbol completion.
+     */
+    public enum AttributionKind {
+        /**
+         * Attribution of superclass (i.e. @{code extends} clause).
+         */
+        EXTENDS {
+            @Override
+            String format(JCTree tree) {
+                return "extends " + super.format(tree);
+            }
+        },
+        /**
+         * Attribution of superinterface (i.e. an type in the @{code interface} clause).
+         */
+        IMPLEMENTS {
+            @Override
+            String format(JCTree tree) {
+                return "implements " + super.format(tree);
+            }
+        },
+        /**
+         * Attribution of an import statement
+         */
+        IMPORT,
+        /**
+         * Attribution of type-variable bound
+         */
+        TVAR {
+            @Override
+            String format(JCTree tree) {
+                return "<" + super.format(tree) + ">";
+            }
+        };
+
+        String format(JCTree tree) {
+            return tree.toString();
+        }
+    }
+
+    /**
+     * Push a new completion node on the stack.
+     */
+    abstract public void push(ClassSymbol s);
+
+    /**
+     * Push a new attribution node on the stack.
+     */
+    abstract public void push(AttributionKind ak, JCTree t);
+
+    /**
+     * Remove current dependency node from the stack.
+     */
+    abstract public void pop();
+
+    /**
+     * This class creates a graph of all dependencies as symbols are completed;
+     * when compilation finishes, the resulting dependecy graph is then dumped
+     * onto a dot file. Several options are provided to customise the output of the graph.
+     */
+    public static class GraphDependencies extends Dependencies implements Closeable, Completer {
+
+        /**
+         * set of enabled dependencies modes
+         */
+        private EnumSet<DependenciesMode> dependenciesModes;
+
+        /**
+         * file in which the dependency graph should be written
+         */
+        private String dependenciesFile;
+
+        /**
+         * Register a Context.Factory to create a Dependencies.
+         */
+        public static void preRegister(final Context context) {
+            context.put(dependenciesKey, new Context.Factory<Dependencies>() {
+                public Dependencies make(Context c) {
+                    Dependencies deps = new GraphDependencies(context);
+                    return deps;
+                }
+            });
+        }
+
+        /**
+         * Build a Dependencies instance.
+         */
+        GraphDependencies(Context context) {
+            super(context);
+            Options options = Options.instance(context);
+            //fetch filename
+            String[] modes = options.get("completionDeps").split(",");
+            for (String mode : modes) {
+                if (mode.startsWith("file=")) {
+                    dependenciesFile = mode.substring(5);
+                }
+            }
+            //parse modes
+            dependenciesModes = DependenciesMode.getDependenciesModes(modes);
+            //add to closeables
+            JavaCompiler compiler = JavaCompiler.instance(context);
+            compiler.closeables = compiler.closeables.prepend(this);
+        }
+
+        enum DependenciesMode {
+            SOURCE("source"),
+            CLASS("class"),
+            REDUNDANT("redundant"),
+            SIDE_EFFECTS("side-effects");
+
+            final String opt;
+
+            private DependenciesMode(String opt) {
+                this.opt = opt;
+            }
+
+            /**
+             * This method is used to parse the {@code completionDeps} option.
+             * Possible modes are separated by colon; a mode can be excluded by
+             * prepending '-' to its name. Finally, the special mode 'all' can be used to
+             * add all modes to the resulting enum.
+             */
+            static EnumSet<DependenciesMode> getDependenciesModes(String[] modes) {
+                EnumSet<DependenciesMode> res = EnumSet.noneOf(DependenciesMode.class);
+                Collection<String> args = Arrays.asList(modes);
+                if (args.contains("all")) {
+                    res = EnumSet.allOf(DependenciesMode.class);
+                }
+                for (DependenciesMode mode : values()) {
+                    if (args.contains(mode.opt)) {
+                        res.add(mode);
+                    } else if (args.contains("-" + mode.opt)) {
+                        res.remove(mode);
+                    }
+                }
+                return res;
+            }
+        }
+
+        /**
+         * Class representing a node in the dependency graph. Nodes are of two main
+         * kinds: (i) symbol nodes, corresponding to symbol completion requests
+         * (either from source or classfile); (ii) attribution nodes, corresponding to
+         * attribution actions triggered during (source) completion.
+         */
+        static abstract class Node extends GraphUtils.AbstractNode<String, Node>
+                implements GraphUtils.DottableNode<String, Node> {
+
+            /**
+             * Model the dependencies between nodes.
+             */
+            enum DependencyKind implements GraphUtils.DependencyKind {
+                /**
+                 * standard dependency - i.e. completion of the source node depends
+                 * on completion of the sink node.
+                 */
+                REQUIRES("solid"),
+                /**
+                 * soft dependencies - i.e. completion of the source node depends
+                 * on side-effects of the source node. These dependencies are meant
+                 * to capture the order in which javac processes all dependants of a given node.
+                 */
+                SIDE_EFFECTS("dashed");
+
+                final String dotStyle;
+
+                DependencyKind(String dotStyle) {
+                    this.dotStyle = dotStyle;
+                }
+            }
+
+            /**
+             * dependant nodes grouped by kind
+             */
+            EnumMap<DependencyKind, List<Node>> depsByKind;
+
+            Node(String value) {
+                super(value);
+                this.depsByKind = new EnumMap<>(DependencyKind.class);
+                for (DependencyKind depKind : DependencyKind.values()) {
+                    depsByKind.put(depKind, new ArrayList<Node>());
+                }
+            }
+
+            void addDependency(DependencyKind depKind, Node dep) {
+                List<Node> deps = depsByKind.get(depKind);
+                if (!deps.contains(dep)) {
+                    deps.add(dep);
+                }
+            }
+
+            @Override
+            public boolean equals(Object obj) {
+                return obj instanceof Node &&
+                        data.equals(((Node) obj).data);
+            }
+
+            @Override
+            public int hashCode() {
+                return data.hashCode();
+            }
+
+            @Override
+            public GraphUtils.DependencyKind[] getSupportedDependencyKinds() {
+                return DependencyKind.values();
+            }
+
+            @Override
+            public java.util.Collection<? extends Node> getDependenciesByKind(GraphUtils.DependencyKind dk) {
+                List<Node> deps = depsByKind.get(dk);
+                if (dk == DependencyKind.REQUIRES) {
+                    return deps;
+                } else {
+                    Set<Node> temp = new HashSet<>(deps);
+                    temp.removeAll(depsByKind.get(DependencyKind.REQUIRES));
+                    return temp;
+                }
+            }
+
+            @Override
+            public Properties nodeAttributes() {
+                Properties p = new Properties();
+                p.put("label", DotVisitor.wrap(toString()));
+                return p;
+            }
+
+            @Override
+            public Properties dependencyAttributes(Node to, GraphUtils.DependencyKind dk) {
+                Properties p = new Properties();
+                p.put("style", ((DependencyKind) dk).dotStyle);
+                return p;
+            }
+        }
+
+        /**
+         * This is a dependency node used to model symbol completion requests.
+         * Completion requests can come from either source or class.
+         */
+        static class CompletionNode extends Node {
+
+            /**
+             * Completion kind (source vs. classfile)
+             */
+            enum Kind {
+                /**
+                 * Source completion request
+                 */
+                SOURCE("solid"),
+                /**
+                 * Classfile completion request
+                 */
+                CLASS("dotted");
+
+                final String dotStyle;
+
+                Kind(String dotStyle) {
+                    this.dotStyle = dotStyle;
+                }
+            }
+
+            final Kind ck;
+
+            CompletionNode(ClassSymbol sym) {
+                super(sym.getQualifiedName().toString());
+                //infer completion kind by looking at the symbol fields
+                boolean fromClass = (sym.classfile == null && sym.sourcefile == null) ||
+                        (sym.classfile != null && sym.classfile.getKind() == JavaFileObject.Kind.CLASS);
+                ck = fromClass ?
+                        CompletionNode.Kind.CLASS :
+                        CompletionNode.Kind.SOURCE;
+            }
+
+            @Override
+            public Properties nodeAttributes() {
+                Properties p = super.nodeAttributes();
+                p.put("style", ck.dotStyle);
+                p.put("shape", "ellipse");
+                return p;
+            }
+        }
+
+        /**
+         * This is a dependency node used to model attribution actions triggered during
+         * source symbol completion. The possible kinds of attribution actions are
+         * captured in {@link AttributionNode}.
+         */
+        static class AttributionNode extends Node {
+
+            AttributionNode(AttributionKind ak, JCTree tree) {
+                super(ak.format(tree));
+            }
+
+            @Override
+            public Properties nodeAttributes() {
+                Properties p = super.nodeAttributes();
+                p.put("shape", "box");
+                p.put("style", "solid");
+                return p;
+            }
+        }
+
+        /**
+         * stack of dependency nodes currently being processed
+         */
+        Stack<Node> nodeStack = new Stack<>();
+
+        /**
+         * map containing all dependency nodes seen so far
+         */
+        Map<String, Node> dependencyNodeMap = new LinkedHashMap<>();
+
+        @Override
+        public void push(ClassSymbol s) {
+            Node n = new CompletionNode(s);
+            if (n == push(n)) {
+                s.completer = this;
+            }
+        }
+
+        @Override
+        public void push(AttributionKind ak, JCTree t) {
+            push(new AttributionNode(ak, t));
+        }
+
+        /**
+         * Push a new dependency on the stack.
+         */
+        protected Node push(Node newNode) {
+            Node cachedNode = dependencyNodeMap.get(newNode.data);
+            if (cachedNode == null) {
+                dependencyNodeMap.put(newNode.data, newNode);
+            } else {
+                newNode = cachedNode;
+            }
+            if (!nodeStack.isEmpty()) {
+                Node currentNode = nodeStack.peek();
+                currentNode.addDependency(Node.DependencyKind.REQUIRES, newNode);
+            }
+            nodeStack.push(newNode);
+            return newNode;
+        }
+
+        @Override
+        public void pop() {
+            nodeStack.pop();
+        }
+
+        @Override
+        public void close() throws IOException {
+            if (dependenciesFile != null) {
+                if (!dependenciesModes.contains(DependenciesMode.REDUNDANT)) {
+                    //prune spurious edges
+                    new PruneVisitor().visit(dependencyNodeMap.values(), null);
+                }
+                if (!dependenciesModes.contains(DependenciesMode.CLASS)) {
+                    //filter class completions
+                    new FilterVisitor(CompletionNode.Kind.SOURCE).visit(dependencyNodeMap.values(), null);
+                }
+                if (!dependenciesModes.contains(DependenciesMode.SOURCE)) {
+                    //filter source completions
+                    new FilterVisitor(CompletionNode.Kind.CLASS).visit(dependencyNodeMap.values(), null);
+                }
+                if (dependenciesModes.contains(DependenciesMode.SIDE_EFFECTS)) {
+                    //add side-effects edges
+                    new SideEffectVisitor().visit(dependencyNodeMap.values(), null);
+                }
+                //write to file
+                try (FileWriter fw = new FileWriter(dependenciesFile)) {
+                    fw.append(GraphUtils.toDot(dependencyNodeMap.values(), "CompletionDeps", ""));
+                }
+            }
+        }
+
+        @Override
+        public void complete(Symbol sym) throws CompletionFailure {
+            push((ClassSymbol) sym);
+            pop();
+            sym.completer = this;
+        }
+
+        /**
+         * This visitor is used to generate the special side-effect dependencies
+         * given a graph containing only standard dependencies.
+         */
+        private static class SideEffectVisitor extends NodeVisitor<String, Node, Void> {
+            @Override
+            public void visitNode(Node node, Void arg) {
+                //do nothing
+            }
+
+            @Override
+            public void visitDependency(GraphUtils.DependencyKind dk, Node from, Node to, Void arg) {
+                //if we are adding multiple dependencies to same node
+                //make order explicit via special 'side-effect' dependencies
+                List<Node> deps = from.depsByKind.get(dk);
+                int pos = deps.indexOf(to);
+                if (dk == Node.DependencyKind.REQUIRES && pos > 0) {
+                    to.addDependency(Node.DependencyKind.SIDE_EFFECTS, deps.get(pos - 1));
+                }
+            }
+        }
+
+        /**
+         * This visitor is used to prune the graph from spurious edges using some heuristics.
+         */
+        private static class PruneVisitor extends NodeVisitor<String, Node, Void> {
+            @Override
+            public void visitNode(Node node, Void arg) {
+                //do nothing
+            }
+
+            @Override
+            public void visitDependency(GraphUtils.DependencyKind dk, Node from, Node to, Void arg) {
+                //heuristic - skips dependencies that are likely to be fake
+                if (from.equals(to) ||
+                        from.depsByKind.get(Node.DependencyKind.REQUIRES).contains(to)) {
+                    to.depsByKind.get(dk).remove(from);
+                }
+            }
+        }
+
+        /**
+         * This visitor is used to retain only completion nodes with given kind.
+         */
+        private class FilterVisitor extends NodeVisitor<String, Node, Void> {
+
+            CompletionNode.Kind ck;
+
+            private FilterVisitor(CompletionNode.Kind ck) {
+                this.ck = ck;
+            }
+
+            @Override
+            public void visitNode(Node node, Void arg) {
+                if (node instanceof CompletionNode) {
+                    if (((CompletionNode) node).ck != ck) {
+                        dependencyNodeMap.remove(node.data);
+                    }
+                }
+            }
+
+            @Override
+            public void visitDependency(GraphUtils.DependencyKind dk, Node from, Node to, Void arg) {
+                if (to instanceof CompletionNode) {
+                    if (((CompletionNode) to).ck != ck) {
+                        from.depsByKind.get(dk).remove(to);
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Dummy class to be used when dependencies options are not set. This keeps
+     * performance cost of calling push/pop methods during completion marginally low.
+     */
+    private static class DummyDependencies extends Dependencies {
+
+        private DummyDependencies(Context context) {
+            super(context);
+        }
+
+        @Override
+        public void push(ClassSymbol s) {
+            //do nothing
+        }
+
+        @Override
+        public void push(AttributionKind ak, JCTree t) {
+            //do nothing
+        }
+
+        @Override
+        public void pop() {
+            //do nothing
+        }
+    }
+}
--- a/langtools/src/share/classes/com/sun/tools/javac/util/GraphUtils.java	Wed Jul 23 09:19:23 2014 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/util/GraphUtils.java	Thu Jul 24 13:11:03 2014 +0100
@@ -25,6 +25,10 @@
 
 package com.sun.tools.javac.util;
 
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Properties;
+
 /** <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
@@ -33,25 +37,65 @@
 public class GraphUtils {
 
     /**
-     * Basic interface for defining various dependency kinds. All dependency kinds
-     * must at least support basic capabilities to tell the DOT engine how to render them.
+     * Basic interface for defining various dependency kinds.
      */
-    public interface DependencyKind {
+    public interface DependencyKind { }
+
+    /**
+     * Common superinterfaces to all graph nodes.
+     */
+    public interface Node<D, N extends Node<D, N>> {
         /**
-         * Returns the DOT representation (to be used in a {@code style} attribute
-         * that's most suited for this dependency kind.
+         * visitor method.
          */
-        String getDotStyle();
+        <A> void accept(NodeVisitor<D, N, A> visitor, A arg);
+    }
+
+    /**
+     * Visitor for graph nodes.
+     */
+    static abstract class NodeVisitor<D, N extends Node<D, N>, A> {
+        /**
+         * Visitor action for nodes.
+         */
+        public abstract void visitNode(N node, A arg);
+        /**
+         * Visitor action for a dependency between 'from' and 'to' with given kind.
+         */
+        public abstract void visitDependency(DependencyKind dk, N from, N to, A arg);
+
+        /**
+         * Visitor entry point.
+         */
+        public void visit(Collection<? extends N> nodes, A arg) {
+            for (N n : new ArrayList<>(nodes)) {
+                n.accept(this, arg);
+            }
+        }
+    }
+
+    /**
+     * Optional interface for nodes supporting dot-based representation.
+     */
+    public interface DottableNode<D, N extends DottableNode<D, N>> extends Node<D, N> {
+        /**
+         * Retrieves the set of dot attributes associated with the node.
+         */
+        Properties nodeAttributes();
+        /**
+         * Retrieves the set of dot attributes associated with a given dependency.
+         */
+        Properties dependencyAttributes(N to, DependencyKind dk);
     }
 
     /**
      * This class is a basic abstract class for representing a node.
      * A node is associated with a given data.
      */
-    public static abstract class Node<D> {
+    public static abstract class AbstractNode<D, N extends AbstractNode<D, N>> implements Node<D, N> {
         public final D data;
 
-        public Node(D data) {
+        public AbstractNode(D data) {
             this.data = data;
         }
 
@@ -61,26 +105,32 @@
         public abstract DependencyKind[] getSupportedDependencyKinds();
 
         /**
-         * Get all dependencies, regardless of their kind.
+         * Get all dependencies of a given kind
          */
-        public abstract Iterable<? extends Node<D>> getAllDependencies();
-
-        /**
-         * Get a name for the dependency (of given kind) linking this node to a given node
-         */
-        public abstract String getDependencyName(Node<D> to, DependencyKind dk);
+        public abstract Collection<? extends N> getDependenciesByKind(DependencyKind dk);
 
         @Override
         public String toString() {
             return data.toString();
         }
+
+        @SuppressWarnings("unchecked")
+        public <A> void accept(NodeVisitor<D, N, A> visitor, A arg) {
+            visitor.visitNode((N)this, arg);
+            for (DependencyKind dk : getSupportedDependencyKinds()) {
+                for (N dep : new ArrayList<>(getDependenciesByKind(dk))) {
+                    visitor.visitDependency(dk, (N)this, dep, arg);
+                }
+            }
+        }
     }
 
     /**
      * This class specialized Node, by adding elements that are required in order
      * to perform Tarjan computation of strongly connected components.
      */
-    public static abstract class TarjanNode<D> extends Node<D> implements Comparable<TarjanNode<D>> {
+    public static abstract class TarjanNode<D, N extends TarjanNode<D, N>> extends AbstractNode<D, N>
+            implements Comparable<N> {
         int index = -1;
         int lowlink;
         boolean active;
@@ -89,11 +139,9 @@
             super(data);
         }
 
-        public abstract Iterable<? extends TarjanNode<D>> getAllDependencies();
+        public abstract Iterable<? extends N> getAllDependencies();
 
-        public abstract Iterable<? extends TarjanNode<D>> getDependenciesByKind(DependencyKind dk);
-
-        public int compareTo(TarjanNode<D> o) {
+        public int compareTo(N o) {
             return (index < o.index) ? -1 : (index == o.index) ? 0 : 1;
         }
     }
@@ -102,7 +150,7 @@
      * Tarjan's algorithm to determine strongly connected components of a
      * directed graph in linear time. Works on TarjanNode.
      */
-    public static <D, N extends TarjanNode<D>> List<? extends List<? extends N>> tarjan(Iterable<? extends N> nodes) {
+    public static <D, N extends TarjanNode<D, N>> List<? extends List<? extends N>> tarjan(Iterable<? extends N> nodes) {
         ListBuffer<List<N>> cycles = new ListBuffer<>();
         ListBuffer<N> stack = new ListBuffer<>();
         int index = 0;
@@ -114,15 +162,13 @@
         return cycles.toList();
     }
 
-    private static <D, N extends TarjanNode<D>> int tarjan(N v, int index, ListBuffer<N> stack, ListBuffer<List<N>> cycles) {
+    private static <D, N extends TarjanNode<D, N>> int tarjan(N v, int index, ListBuffer<N> stack, ListBuffer<List<N>> cycles) {
         v.index = index;
         v.lowlink = index;
         index++;
         stack.prepend(v);
         v.active = true;
-        for (TarjanNode<D> nd: v.getAllDependencies()) {
-            @SuppressWarnings("unchecked")
-            N n = (N)nd;
+        for (N n: v.getAllDependencies()) {
             if (n.index == -1) {
                 tarjan(n, index, stack, cycles);
                 v.lowlink = Math.min(v.lowlink, n.lowlink);
@@ -149,24 +195,45 @@
      * and {@code Node.printDependency} to display edge labels. The resulting
      * representation is also customizable with a graph name and a header.
      */
-    public static <D> String toDot(Iterable<? extends TarjanNode<D>> nodes, String name, String header) {
+    public static <D, N extends DottableNode<D, N>> String toDot(Collection<? extends N> nodes, String name, String header) {
         StringBuilder buf = new StringBuilder();
         buf.append(String.format("digraph %s {\n", name));
-        buf.append(String.format("label = \"%s\";\n", header));
-        //dump nodes
-        for (TarjanNode<D> n : nodes) {
-            buf.append(String.format("%s [label = \"%s\"];\n", n.hashCode(), n.toString()));
-        }
-        //dump arcs
-        for (TarjanNode<D> from : nodes) {
-            for (DependencyKind dk : from.getSupportedDependencyKinds()) {
-                for (TarjanNode<D> to : from.getDependenciesByKind(dk)) {
-                    buf.append(String.format("%s -> %s [label = \" %s \" style = %s ];\n",
-                            from.hashCode(), to.hashCode(), from.getDependencyName(to, dk), dk.getDotStyle()));
-                }
-            }
-        }
+        buf.append(String.format("label = %s;\n", DotVisitor.wrap(header)));
+        DotVisitor<D, N> dotVisitor = new DotVisitor<>();
+        dotVisitor.visit(nodes, buf);
         buf.append("}\n");
         return buf.toString();
     }
+
+    /**
+     * This visitor is used to dump the contents of a set of nodes of type {@link DottableNode}
+     * onto a string builder.
+     */
+    public static class DotVisitor<D, N extends DottableNode<D, N>> extends NodeVisitor<D, N, StringBuilder> {
+
+        @Override
+        public void visitDependency(DependencyKind dk, N from, N to, StringBuilder buf) {
+            buf.append(String.format("%s -> %s", from.hashCode(), to.hashCode()));
+            buf.append(formatProperties(from.dependencyAttributes(to, dk)));
+            buf.append('\n');
+        }
+
+        @Override
+        public void visitNode(N node, StringBuilder buf) {
+            buf.append(String.format("%s ", node.hashCode()));
+            buf.append(formatProperties(node.nodeAttributes()));
+            buf.append('\n');
+        }
+
+        protected String formatProperties(Properties p) {
+            return p.toString().replaceAll(",", " ")
+                .replaceAll("\\{", "[")
+                .replaceAll("\\}", "]");
+        }
+
+        protected static String wrap(String s) {
+            String res = "\"" + s + "\"";
+            return res.replaceAll("\n", "");
+        }
+    }
 }