langtools/src/share/classes/com/sun/tools/javac/code/TypeAnnotations.java
changeset 15385 ee1eebe7e210
child 15718 8e54c8e43d38
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/code/TypeAnnotations.java	Wed Jan 23 13:27:24 2013 -0800
@@ -0,0 +1,1037 @@
+/*
+ * Copyright (c) 2009, 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.  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.code;
+
+import javax.lang.model.element.Element;
+import javax.lang.model.element.ElementKind;
+import javax.lang.model.type.TypeKind;
+
+import com.sun.tools.javac.code.Attribute;
+import com.sun.tools.javac.code.Attribute.TypeCompound;
+import com.sun.tools.javac.code.Flags;
+import com.sun.tools.javac.code.Kinds;
+import com.sun.tools.javac.code.Type.AnnotatedType;
+import com.sun.tools.javac.code.Type.ArrayType;
+import com.sun.tools.javac.code.Type.CapturedType;
+import com.sun.tools.javac.code.Type.ClassType;
+import com.sun.tools.javac.code.Type.ErrorType;
+import com.sun.tools.javac.code.Type.ForAll;
+import com.sun.tools.javac.code.Type.MethodType;
+import com.sun.tools.javac.code.Type.PackageType;
+import com.sun.tools.javac.code.Type.TypeVar;
+import com.sun.tools.javac.code.Type.UndetVar;
+import com.sun.tools.javac.code.Type.Visitor;
+import com.sun.tools.javac.code.Type.WildcardType;
+import com.sun.tools.javac.code.TypeAnnotationPosition.TypePathEntry;
+import com.sun.tools.javac.code.TypeAnnotationPosition.TypePathEntryKind;
+import com.sun.tools.javac.code.TypeTag;
+import com.sun.tools.javac.code.Symbol.VarSymbol;
+import com.sun.tools.javac.comp.Annotate.Annotator;
+import com.sun.tools.javac.tree.JCTree;
+import com.sun.tools.javac.tree.JCTree.JCBlock;
+import com.sun.tools.javac.tree.JCTree.JCClassDecl;
+import com.sun.tools.javac.tree.JCTree.JCExpression;
+import com.sun.tools.javac.tree.JCTree.JCMethodDecl;
+import com.sun.tools.javac.tree.JCTree.JCTypeApply;
+import com.sun.tools.javac.tree.JCTree.JCVariableDecl;
+import com.sun.tools.javac.tree.TreeScanner;
+import com.sun.tools.javac.tree.JCTree.*;
+import com.sun.tools.javac.util.Assert;
+import com.sun.tools.javac.util.List;
+import com.sun.tools.javac.util.ListBuffer;
+import com.sun.tools.javac.util.Log;
+import com.sun.tools.javac.util.Names;
+
+/**
+ * Contains operations specific to processing type annotations.
+ * This class has two functions:
+ * separate declaration from type annotations and insert the type
+ * annotations to their types;
+ * and determine the TypeAnnotationPositions for all type annotations.
+ */
+public class TypeAnnotations {
+    // Class cannot be instantiated.
+    private TypeAnnotations() {}
+
+    /**
+     * Separate type annotations from declaration annotations and
+     * determine the correct positions for type annotations.
+     * This version only visits types in signatures and should be
+     * called from MemberEnter.
+     * The method returns the Annotator object that should be added
+     * to the correct Annotate queue for later processing.
+     */
+    public static Annotator organizeTypeAnnotationsSignatures(final Symtab syms, final Names names,
+            final Log log, final JCClassDecl tree) {
+        return new Annotator() {
+            @Override
+            public void enterAnnotation() {
+                new TypeAnnotationPositions(syms, names, log, true).scan(tree);
+            }
+        };
+    }
+
+    /**
+     * This version only visits types in bodies, that is, field initializers,
+     * top-level blocks, and method bodies, and should be called from Attr.
+     */
+    public static void organizeTypeAnnotationsBodies(Symtab syms, Names names, Log log, JCClassDecl tree) {
+        new TypeAnnotationPositions(syms, names, log, false).scan(tree);
+    }
+
+    private static class TypeAnnotationPositions extends TreeScanner {
+
+        private enum AnnotationType { DECLARATION, TYPE, BOTH };
+
+        private final Symtab syms;
+        private final Names names;
+        private final Log log;
+        private final boolean sigOnly;
+
+        private TypeAnnotationPositions(Symtab syms, Names names, Log log, boolean sigOnly) {
+            this.syms = syms;
+            this.names = names;
+            this.log = log;
+            this.sigOnly = sigOnly;
+        }
+
+        /*
+         * When traversing the AST we keep the "frames" of visited
+         * trees in order to determine the position of annotations.
+         */
+        private ListBuffer<JCTree> frames = ListBuffer.lb();
+
+        protected void push(JCTree t) { frames = frames.prepend(t); }
+        protected JCTree pop() { return frames.next(); }
+        // could this be frames.elems.tail.head?
+        private JCTree peek2() { return frames.toList().tail.head; }
+
+        @Override
+        public void scan(JCTree tree) {
+            push(tree);
+            super.scan(tree);
+            pop();
+        }
+
+        /**
+         * Separates type annotations from declaration annotations.
+         * This step is needed because in certain locations (where declaration
+         * and type annotations can be mixed, e.g. the type of a field)
+         * we never build an JCAnnotatedType. This step finds these
+         * annotations and marks them as if they were part of the type.
+         */
+        private void separateAnnotationsKinds(JCTree typetree, Type type, Symbol sym,
+                TypeAnnotationPosition pos) {
+            /*
+            System.out.printf("separateAnnotationsKinds(typetree: %s, type: %s, symbol: %s, pos: %s%n",
+                    typetree, type, sym, pos);
+            */
+            List<Attribute.Compound> annotations = sym.getRawAttributes();
+            ListBuffer<Attribute.Compound> declAnnos = new ListBuffer<Attribute.Compound>();
+            ListBuffer<Attribute.TypeCompound> typeAnnos = new ListBuffer<Attribute.TypeCompound>();
+
+            for (Attribute.Compound a : annotations) {
+                switch (annotationType(a, sym)) {
+                case DECLARATION:
+                    declAnnos.append(a);
+                    break;
+                case BOTH: {
+                    declAnnos.append(a);
+                    Attribute.TypeCompound ta = toTypeCompound(a, pos);
+                    typeAnnos.append(ta);
+                    break;
+                }
+                case TYPE: {
+                    Attribute.TypeCompound ta = toTypeCompound(a, pos);
+                    typeAnnos.append(ta);
+                    break;
+                }
+                }
+            }
+
+            sym.annotations.reset();
+            sym.annotations.setDeclarationAttributes(declAnnos.toList());
+
+            List<Attribute.TypeCompound> typeAnnotations = typeAnnos.toList();
+
+            if (type == null) {
+                // When type is null, put the type annotations to the symbol.
+                // This is used for constructor return annotations, for which
+                // no appropriate type exists.
+                sym.annotations.appendUniqueTypes(typeAnnotations);
+                return;
+            }
+
+            // type is non-null and annotations are added to that type
+            type = typeWithAnnotations(typetree, type, typeAnnotations, log);
+
+            if (sym.getKind() == ElementKind.METHOD) {
+                sym.type.asMethodType().restype = type;
+            } else {
+                sym.type = type;
+            }
+
+            sym.annotations.appendUniqueTypes(typeAnnotations);
+            if (sym.getKind() == ElementKind.PARAMETER &&
+                    sym.getQualifiedName().equals(names._this)) {
+                sym.owner.type.asMethodType().recvtype = type;
+                // note that the typeAnnotations will also be added to the owner below.
+            }
+            if (sym.getKind() == ElementKind.PARAMETER ||
+                    sym.getKind() == ElementKind.LOCAL_VARIABLE ||
+                    sym.getKind() == ElementKind.RESOURCE_VARIABLE ||
+                    sym.getKind() == ElementKind.EXCEPTION_PARAMETER) {
+                // Make sure all type annotations from the symbol are also
+                // on the owner.
+                sym.owner.annotations.appendUniqueTypes(sym.getTypeAnnotationMirrors());
+            }
+        }
+
+        // This method has a similar purpose as
+        // {@link com.sun.tools.javac.parser.JavacParser.insertAnnotationsToMostInner(JCExpression, List<JCTypeAnnotation>, boolean)}
+        // We found a type annotation in a declaration annotation position,
+        // for example, on the return type.
+        // Such an annotation is _not_ part of an JCAnnotatedType tree and we therefore
+        // need to set its position explicitly.
+        // The method returns a copy of type that contains these annotations.
+        private static Type typeWithAnnotations(final JCTree typetree, final Type type,
+                final List<Attribute.TypeCompound> annotations, Log log) {
+            // System.out.printf("typeWithAnnotations(typetree: %s, type: %s, annotations: %s)%n",
+            //         typetree, type, annotations);
+            if (annotations.isEmpty()) {
+                return type;
+            }
+            if (type.hasTag(TypeTag.ARRAY)) {
+                Type toreturn;
+                Type.ArrayType tomodify;
+                Type.ArrayType arType;
+                {
+                    Type touse = type;
+                    if (type.getKind() == TypeKind.ANNOTATED) {
+                        Type.AnnotatedType atype = (Type.AnnotatedType)type;
+                        toreturn = new Type.AnnotatedType(atype.underlyingType);
+                        ((Type.AnnotatedType)toreturn).typeAnnotations = atype.typeAnnotations;
+                        touse = atype.underlyingType;
+                        arType = (Type.ArrayType) touse;
+                        tomodify = new Type.ArrayType(null, arType.tsym);
+                        ((Type.AnnotatedType)toreturn).underlyingType = tomodify;
+                    } else {
+                        arType = (Type.ArrayType) touse;
+                        tomodify = new Type.ArrayType(null, arType.tsym);
+                        toreturn = tomodify;
+                    }
+                }
+                JCArrayTypeTree arTree = arrayTypeTree(typetree);
+
+                ListBuffer<TypePathEntry> depth = ListBuffer.lb();
+                depth = depth.append(TypePathEntry.ARRAY);
+                while (arType.elemtype.hasTag(TypeTag.ARRAY)) {
+                    if (arType.elemtype.getKind() == TypeKind.ANNOTATED) {
+                        Type.AnnotatedType aelemtype = (Type.AnnotatedType) arType.elemtype;
+                        Type.AnnotatedType newAT = new Type.AnnotatedType(aelemtype.underlyingType);
+                        tomodify.elemtype = newAT;
+                        newAT.typeAnnotations = aelemtype.typeAnnotations;
+                        arType = (Type.ArrayType) aelemtype.underlyingType;
+                        tomodify = new Type.ArrayType(null, arType.tsym);
+                        newAT.underlyingType = tomodify;
+                    } else {
+                        arType = (Type.ArrayType) arType.elemtype;
+                        tomodify.elemtype = new Type.ArrayType(null, arType.tsym);
+                        tomodify = (Type.ArrayType) tomodify.elemtype;
+                    }
+                    arTree = arrayTypeTree(arTree.elemtype);
+                    depth = depth.append(TypePathEntry.ARRAY);
+                }
+                Type arelemType = typeWithAnnotations(arTree.elemtype, arType.elemtype, annotations, log);
+                tomodify.elemtype = arelemType;
+                for (Attribute.TypeCompound a : annotations) {
+                    TypeAnnotationPosition p = a.position;
+                    p.location = p.location.prependList(depth.toList());
+                }
+                return toreturn;
+            } else if (type.hasTag(TypeTag.TYPEVAR)) {
+                // Nothing to do for type variables.
+                return type;
+            } else {
+                Type enclTy = type;
+                Element enclEl = type.asElement();
+                JCTree enclTr = typetree;
+
+                while (enclEl != null &&
+                        enclEl.getKind() != ElementKind.PACKAGE &&
+                        enclTy != null &&
+                        enclTy.getKind() != TypeKind.NONE &&
+                        enclTy.getKind() != TypeKind.ERROR &&
+                        (enclTr.getKind() == JCTree.Kind.MEMBER_SELECT ||
+                         enclTr.getKind() == JCTree.Kind.PARAMETERIZED_TYPE ||
+                         enclTr.getKind() == JCTree.Kind.ANNOTATED_TYPE)) {
+                    // Iterate also over the type tree, not just the type: the type is already
+                    // completely resolved and we cannot distinguish where the annotation
+                    // belongs for a nested type.
+                    if (enclTr.getKind() == JCTree.Kind.MEMBER_SELECT) {
+                        // only change encl in this case.
+                        enclTy = enclTy.getEnclosingType();
+                        enclEl = enclEl.getEnclosingElement();
+                        enclTr = ((JCFieldAccess)enclTr).getExpression();
+                    } else if (enclTr.getKind() == JCTree.Kind.PARAMETERIZED_TYPE) {
+                        enclTr = ((JCTypeApply)enclTr).getType();
+                    } else {
+                        // only other option because of while condition
+                        enclTr = ((JCAnnotatedType)enclTr).getUnderlyingType();
+                    }
+                }
+
+                /** We are trying to annotate some enclosing type,
+                 * but nothing more exists.
+                 */
+                if (enclTy != null &&
+                        enclTy.getKind() == TypeKind.NONE &&
+                        (enclTr.getKind() == JCTree.Kind.IDENTIFIER ||
+                         enclTr.getKind() == JCTree.Kind.MEMBER_SELECT ||
+                         enclTr.getKind() == JCTree.Kind.PARAMETERIZED_TYPE ||
+                         enclTr.getKind() == JCTree.Kind.ANNOTATED_TYPE)) {
+                    // TODO: also if it's "java. @A lang.Object", that is,
+                    // if it's on a package?
+                    log.error(enclTr.pos(), "cant.annotate.nested.type", enclTr.toString());
+                    return type;
+                }
+
+                // At this point we have visited the part of the nested
+                // type that is written in the source code.
+                // Now count from here to the actual top-level class to determine
+                // the correct nesting.
+
+                // The genericLocation for the annotation.
+                ListBuffer<TypePathEntry> depth = ListBuffer.lb();
+
+                Type topTy = enclTy;
+                while (enclEl != null &&
+                        enclEl.getKind() != ElementKind.PACKAGE &&
+                        topTy != null &&
+                        topTy.getKind() != TypeKind.NONE &&
+                        topTy.getKind() != TypeKind.ERROR) {
+                    topTy = topTy.getEnclosingType();
+                    enclEl = enclEl.getEnclosingElement();
+
+                    if (topTy != null && topTy.getKind() != TypeKind.NONE) {
+                        // Only count enclosing types.
+                        depth = depth.append(TypePathEntry.INNER_TYPE);
+                    }
+                }
+
+                if (depth.nonEmpty()) {
+                    // Only need to change the annotation positions
+                    // if they are on an enclosed type.
+                    for (Attribute.TypeCompound a : annotations) {
+                        TypeAnnotationPosition p = a.position;
+                        p.location = p.location.appendList(depth.toList());
+                    }
+                }
+
+                Type ret = typeWithAnnotations(type, enclTy, annotations);
+                return ret;
+            }
+        }
+
+        private static JCArrayTypeTree arrayTypeTree(JCTree typetree) {
+            if (typetree.getKind() == JCTree.Kind.ARRAY_TYPE) {
+                return (JCArrayTypeTree) typetree;
+            } else if (typetree.getKind() == JCTree.Kind.ANNOTATED_TYPE) {
+                return (JCArrayTypeTree) ((JCAnnotatedType)typetree).underlyingType;
+            } else {
+                Assert.error("Could not determine array type from type tree: " + typetree);
+                return null;
+            }
+        }
+
+        /** Return a copy of the first type that only differs by
+         * inserting the annotations to the left-most/inner-most type
+         * or the type given by stopAt.
+         *
+         * We need the stopAt parameter to know where on a type to
+         * put the annotations.
+         * If we have nested classes Outer > Middle > Inner, and we
+         * have the source type "@A Middle.Inner", we will invoke
+         * this method with type = Outer.Middle.Inner,
+         * stopAt = Middle.Inner, and annotations = @A.
+         *
+         * @param type The type to copy.
+         * @param stopAt The type to stop at.
+         * @param annotations The annotations to insert.
+         * @return A copy of type that contains the annotations.
+         */
+        private static Type typeWithAnnotations(final Type type,
+                final Type stopAt,
+                final List<Attribute.TypeCompound> annotations) {
+            Visitor<Type, List<TypeCompound>> visitor =
+                    new Type.Visitor<Type, List<Attribute.TypeCompound>>() {
+                @Override
+                public Type visitClassType(ClassType t, List<TypeCompound> s) {
+                    // assert that t.constValue() == null?
+                    if (t == stopAt ||
+                        t.getEnclosingType() == Type.noType) {
+                        return new AnnotatedType(s, t);
+                    } else {
+                        ClassType ret = new ClassType(t.getEnclosingType().accept(this, s),
+                                t.typarams_field, t.tsym);
+                        ret.all_interfaces_field = t.all_interfaces_field;
+                        ret.allparams_field = t.allparams_field;
+                        ret.interfaces_field = t.interfaces_field;
+                        ret.rank_field = t.rank_field;
+                        ret.supertype_field = t.supertype_field;
+                        return ret;
+                    }
+                }
+
+                @Override
+                public Type visitAnnotatedType(AnnotatedType t, List<TypeCompound> s) {
+                    return new AnnotatedType(t.typeAnnotations, t.underlyingType.accept(this, s));
+                }
+
+                @Override
+                public Type visitWildcardType(WildcardType t, List<TypeCompound> s) {
+                    return new AnnotatedType(s, t);
+                }
+
+                @Override
+                public Type visitArrayType(ArrayType t, List<TypeCompound> s) {
+                    ArrayType ret = new ArrayType(t.elemtype.accept(this, s), t.tsym);
+                    return ret;
+                }
+
+                @Override
+                public Type visitMethodType(MethodType t, List<TypeCompound> s) {
+                    // Impossible?
+                    return t;
+                }
+
+                @Override
+                public Type visitPackageType(PackageType t, List<TypeCompound> s) {
+                    // Impossible?
+                    return t;
+                }
+
+                @Override
+                public Type visitTypeVar(TypeVar t, List<TypeCompound> s) {
+                    return new AnnotatedType(s, t);
+                }
+
+                @Override
+                public Type visitCapturedType(CapturedType t, List<TypeCompound> s) {
+                    return new AnnotatedType(s, t);
+                }
+
+                @Override
+                public Type visitForAll(ForAll t, List<TypeCompound> s) {
+                    // Impossible?
+                    return t;
+                }
+
+                @Override
+                public Type visitUndetVar(UndetVar t, List<TypeCompound> s) {
+                    // Impossible?
+                    return t;
+                }
+
+                @Override
+                public Type visitErrorType(ErrorType t, List<TypeCompound> s) {
+                    return new AnnotatedType(s, t);
+                }
+
+                @Override
+                public Type visitType(Type t, List<TypeCompound> s) {
+                    // Error?
+                    return t;
+                }
+            };
+
+            return type.accept(visitor, annotations);
+        }
+
+        private static Attribute.TypeCompound toTypeCompound(Attribute.Compound a, TypeAnnotationPosition p) {
+            // It is safe to alias the position.
+            return new Attribute.TypeCompound(a, p);
+        }
+
+        private AnnotationType annotationType(Attribute.Compound a, Symbol s) {
+            Attribute.Compound atTarget =
+                a.type.tsym.attribute(syms.annotationTargetType.tsym);
+            if (atTarget == null) {
+                return inferTargetMetaInfo(a, s);
+            }
+            Attribute atValue = atTarget.member(names.value);
+            if (!(atValue instanceof Attribute.Array)) {
+                Assert.error("annotationType(): bad @Target argument " + atValue +
+                        " (" + atValue.getClass() + ")");
+                return AnnotationType.DECLARATION; // error recovery
+            }
+            Attribute.Array arr = (Attribute.Array) atValue;
+            boolean isDecl = false, isType = false;
+            for (Attribute app : arr.values) {
+                if (!(app instanceof Attribute.Enum)) {
+                    Assert.error("annotationType(): unrecognized Attribute kind " + app +
+                            " (" + app.getClass() + ")");
+                    isDecl = true;
+                    continue;
+                }
+                Attribute.Enum e = (Attribute.Enum) app;
+                if (e.value.name == names.TYPE) {
+                    if (s.kind == Kinds.TYP)
+                        isDecl = true;
+                } else if (e.value.name == names.FIELD) {
+                    if (s.kind == Kinds.VAR &&
+                            s.owner.kind != Kinds.MTH)
+                        isDecl = true;
+                } else if (e.value.name == names.METHOD) {
+                    if (s.kind == Kinds.MTH &&
+                            !s.isConstructor())
+                        isDecl = true;
+                } else if (e.value.name == names.PARAMETER) {
+                    if (s.kind == Kinds.VAR &&
+                            s.owner.kind == Kinds.MTH &&
+                            (s.flags() & Flags.PARAMETER) != 0)
+                        isDecl = true;
+                } else if (e.value.name == names.CONSTRUCTOR) {
+                    if (s.kind == Kinds.MTH &&
+                            s.isConstructor())
+                        isDecl = true;
+                } else if (e.value.name == names.LOCAL_VARIABLE) {
+                    if (s.kind == Kinds.VAR &&
+                            s.owner.kind == Kinds.MTH &&
+                            (s.flags() & Flags.PARAMETER) == 0)
+                        isDecl = true;
+                } else if (e.value.name == names.ANNOTATION_TYPE) {
+                    if (s.kind == Kinds.TYP &&
+                            (s.flags() & Flags.ANNOTATION) != 0)
+                        isDecl = true;
+                } else if (e.value.name == names.PACKAGE) {
+                    if (s.kind == Kinds.PCK)
+                        isDecl = true;
+                } else if (e.value.name == names.TYPE_USE) {
+                    if (s.kind == Kinds.TYP ||
+                            s.kind == Kinds.VAR ||
+                            (s.kind == Kinds.MTH && !s.isConstructor() &&
+                            !s.type.getReturnType().hasTag(TypeTag.VOID)) ||
+                            (s.kind == Kinds.MTH && s.isConstructor()))
+                        isType = true;
+                } else if (e.value.name == names.TYPE_PARAMETER) {
+                    /* Irrelevant in this case */
+                    // TYPE_PARAMETER doesn't aid in distinguishing between
+                    // Type annotations and declaration annotations on an
+                    // Element
+                } else {
+                    Assert.error("annotationType(): unrecognized Attribute name " + e.value.name +
+                            " (" + e.value.name.getClass() + ")");
+                    isDecl = true;
+                }
+            }
+            if (isDecl && isType) {
+                return AnnotationType.BOTH;
+            } else if (isType) {
+                return AnnotationType.TYPE;
+            } else {
+                return AnnotationType.DECLARATION;
+            }
+        }
+
+        /** Infer the target annotation kind, if none is give.
+         * We only infer declaration annotations.
+         */
+        private static AnnotationType inferTargetMetaInfo(Attribute.Compound a, Symbol s) {
+            return AnnotationType.DECLARATION;
+        }
+
+
+        /* This is the beginning of the second part of organizing
+         * type annotations: determine the type annotation positions.
+         */
+
+        private void resolveFrame(JCTree tree, JCTree frame,
+                List<JCTree> path, TypeAnnotationPosition p) {
+            /*
+            System.out.println("Resolving tree: " + tree + " kind: " + tree.getKind());
+            System.out.println("    Framing tree: " + frame + " kind: " + frame.getKind());
+            */
+            switch (frame.getKind()) {
+                case TYPE_CAST:
+                    p.type = TargetType.CAST;
+                    p.pos = frame.pos;
+                    return;
+
+                case INSTANCE_OF:
+                    p.type = TargetType.INSTANCEOF;
+                    p.pos = frame.pos;
+                    return;
+
+                case NEW_CLASS:
+                    JCNewClass frameNewClass = (JCNewClass)frame;
+                    if (frameNewClass.typeargs.contains(tree)) {
+                        p.type = TargetType.CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT;
+                        p.type_index = frameNewClass.typeargs.indexOf(tree);
+                    } else {
+                        p.type = TargetType.NEW;
+                    }
+                    p.pos = frame.pos;
+                    return;
+
+                case NEW_ARRAY:
+                    p.type = TargetType.NEW;
+                    p.pos = frame.pos;
+                    return;
+
+                case ANNOTATION_TYPE:
+                case CLASS:
+                case ENUM:
+                case INTERFACE:
+                    p.pos = frame.pos;
+                    if (((JCClassDecl)frame).extending == tree) {
+                        p.type = TargetType.CLASS_EXTENDS;
+                        p.type_index = -1;
+                    } else if (((JCClassDecl)frame).implementing.contains(tree)) {
+                        p.type = TargetType.CLASS_EXTENDS;
+                        p.type_index = ((JCClassDecl)frame).implementing.indexOf(tree);
+                    } else if (((JCClassDecl)frame).typarams.contains(tree)) {
+                        p.type = TargetType.CLASS_TYPE_PARAMETER;
+                        p.parameter_index = ((JCClassDecl)frame).typarams.indexOf(tree);
+                    } else {
+                        Assert.error("Could not determine position of tree " + tree +
+                                " within frame " + frame);
+                    }
+                    return;
+
+                case METHOD: {
+                    JCMethodDecl frameMethod = (JCMethodDecl) frame;
+                    p.pos = frame.pos;
+                    if (frameMethod.thrown.contains(tree)) {
+                        p.type = TargetType.THROWS;
+                        p.type_index = frameMethod.thrown.indexOf(tree);
+                    } else if (frameMethod.restype == tree) {
+                        p.type = TargetType.METHOD_RETURN;
+                    } else if (frameMethod.typarams.contains(tree)) {
+                        p.type = TargetType.METHOD_TYPE_PARAMETER;
+                        p.parameter_index = frameMethod.typarams.indexOf(tree);
+                    } else {
+                        Assert.error("Could not determine position of tree " + tree +
+                                " within frame " + frame);
+                    }
+                    return;
+                }
+
+                case PARAMETERIZED_TYPE: {
+                    if (((JCTypeApply)frame).clazz == tree) {
+                        // generic: RAW; noop
+                    } else if (((JCTypeApply)frame).arguments.contains(tree)) {
+                        JCTypeApply taframe = (JCTypeApply) frame;
+                        int arg = taframe.arguments.indexOf(tree);
+                        p.location = p.location.prepend(new TypePathEntry(TypePathEntryKind.TYPE_ARGUMENT, arg));
+
+                        locateNestedTypes(taframe.type, p);
+                    } else {
+                        Assert.error("Could not determine type argument position of tree " + tree +
+                                " within frame " + frame);
+                    }
+
+                    List<JCTree> newPath = path.tail;
+                    resolveFrame(newPath.head, newPath.tail.head, newPath, p);
+                    return;
+                }
+
+                case ARRAY_TYPE: {
+                    ListBuffer<TypePathEntry> index = ListBuffer.lb();
+                    index = index.append(TypePathEntry.ARRAY);
+                    List<JCTree> newPath = path.tail;
+                    while (true) {
+                        JCTree npHead = newPath.tail.head;
+                        if (npHead.hasTag(JCTree.Tag.TYPEARRAY)) {
+                            newPath = newPath.tail;
+                            index = index.append(TypePathEntry.ARRAY);
+                        } else if (npHead.hasTag(JCTree.Tag.ANNOTATED_TYPE)) {
+                            newPath = newPath.tail;
+                        } else {
+                            break;
+                        }
+                    }
+                    p.location = p.location.prependList(index.toList());
+                    resolveFrame(newPath.head, newPath.tail.head, newPath, p);
+                    return;
+                }
+
+                case TYPE_PARAMETER:
+                    if (path.tail.tail.head.hasTag(JCTree.Tag.CLASSDEF)) {
+                        JCClassDecl clazz = (JCClassDecl)path.tail.tail.head;
+                        p.type = TargetType.CLASS_TYPE_PARAMETER_BOUND;
+                        p.parameter_index = clazz.typarams.indexOf(path.tail.head);
+                        p.bound_index = ((JCTypeParameter)frame).bounds.indexOf(tree);
+                        if (((JCTypeParameter)frame).bounds.get(0).type.isInterface()) {
+                            // Account for an implicit Object as bound 0
+                            p.bound_index += 1;
+                        }
+                    } else if (path.tail.tail.head.hasTag(JCTree.Tag.METHODDEF)) {
+                        JCMethodDecl method = (JCMethodDecl)path.tail.tail.head;
+                        p.type = TargetType.METHOD_TYPE_PARAMETER_BOUND;
+                        p.parameter_index = method.typarams.indexOf(path.tail.head);
+                        p.bound_index = ((JCTypeParameter)frame).bounds.indexOf(tree);
+                        if (((JCTypeParameter)frame).bounds.get(0).type.isInterface()) {
+                            // Account for an implicit Object as bound 0
+                            p.bound_index += 1;
+                        }
+                    } else {
+                        Assert.error("Could not determine position of tree " + tree +
+                                " within frame " + frame);
+                    }
+                    p.pos = frame.pos;
+                    return;
+
+                case VARIABLE:
+                    VarSymbol v = ((JCVariableDecl)frame).sym;
+                    p.pos = frame.pos;
+                    switch (v.getKind()) {
+                        case LOCAL_VARIABLE:
+                            p.type = TargetType.LOCAL_VARIABLE;
+                            break;
+                        case FIELD:
+                            p.type = TargetType.FIELD;
+                            break;
+                        case PARAMETER:
+                            if (v.getQualifiedName().equals(names._this)) {
+                                // TODO: Intro a separate ElementKind?
+                                p.type = TargetType.METHOD_RECEIVER;
+                            } else {
+                                p.type = TargetType.METHOD_FORMAL_PARAMETER;
+                                p.parameter_index = methodParamIndex(path, frame);
+                            }
+                            break;
+                        case EXCEPTION_PARAMETER:
+                            p.type = TargetType.EXCEPTION_PARAMETER;
+                            break;
+                        case RESOURCE_VARIABLE:
+                            p.type = TargetType.RESOURCE_VARIABLE;
+                            break;
+                        default:
+                            Assert.error("Found unexpected type annotation for variable: " + v + " with kind: " + v.getKind());
+                    }
+                    return;
+
+                case ANNOTATED_TYPE: {
+                    if (frame == tree) {
+                        // This is only true for the first annotated type we see.
+                        // For any other annotated types along the path, we do
+                        // not care about inner types.
+                        JCAnnotatedType atypetree = (JCAnnotatedType) frame;
+                        final Type utype = atypetree.underlyingType.type;
+                        Symbol tsym = utype.tsym;
+                        if (tsym.getKind().equals(ElementKind.TYPE_PARAMETER) ||
+                                utype.getKind().equals(TypeKind.WILDCARD) ||
+                                utype.getKind().equals(TypeKind.ARRAY)) {
+                            // Type parameters, wildcards, and arrays have the declaring
+                            // class/method as enclosing elements.
+                            // There is actually nothing to do for them.
+                        } else {
+                            locateNestedTypes(utype, p);
+                        }
+                    }
+                    List<JCTree> newPath = path.tail;
+                    resolveFrame(newPath.head, newPath.tail.head, newPath, p);
+                    return;
+                }
+
+                case UNION_TYPE: {
+                    // TODO: can we store any information here to help in
+                    // determining the final position?
+                    List<JCTree> newPath = path.tail;
+                    resolveFrame(newPath.head, newPath.tail.head, newPath, p);
+                    return;
+                }
+
+                case METHOD_INVOCATION: {
+                    JCMethodInvocation invocation = (JCMethodInvocation)frame;
+                    if (!invocation.typeargs.contains(tree)) {
+                        Assert.error("{" + tree + "} is not an argument in the invocation: " + invocation);
+                    }
+                    p.type = TargetType.METHOD_INVOCATION_TYPE_ARGUMENT;
+                    p.pos = invocation.pos;
+                    p.type_index = invocation.typeargs.indexOf(tree);
+                    return;
+                }
+
+                case EXTENDS_WILDCARD:
+                case SUPER_WILDCARD: {
+                    // Annotations in wildcard bounds
+                    p.location = p.location.prepend(TypePathEntry.WILDCARD);
+                    List<JCTree> newPath = path.tail;
+                    resolveFrame(newPath.head, newPath.tail.head, newPath, p);
+                    return;
+                }
+
+                case MEMBER_SELECT: {
+                    List<JCTree> newPath = path.tail;
+                    resolveFrame(newPath.head, newPath.tail.head, newPath, p);
+                    return;
+                }
+
+                default:
+                    Assert.error("Unresolved frame: " + frame + " of kind: " + frame.getKind() +
+                            "\n    Looking for tree: " + tree);
+                    return;
+            }
+        }
+
+        private static void locateNestedTypes(Type type, TypeAnnotationPosition p) {
+            // The number of "steps" to get from the full type to the
+            // left-most outer type.
+            ListBuffer<TypePathEntry> depth = ListBuffer.lb();
+
+            Type encl = type.getEnclosingType();
+            while (encl != null &&
+                    encl.getKind() != TypeKind.NONE &&
+                    encl.getKind() != TypeKind.ERROR) {
+                depth = depth.append(TypePathEntry.INNER_TYPE);
+                encl = encl.getEnclosingType();
+            }
+            if (depth.nonEmpty()) {
+                p.location = p.location.prependList(depth.toList());
+            }
+        }
+
+        private static int methodParamIndex(List<JCTree> path, JCTree param) {
+            List<JCTree> curr = path;
+            while (curr.head.getTag() != Tag.METHODDEF) {
+                curr = curr.tail;
+            }
+            JCMethodDecl method = (JCMethodDecl)curr.head;
+            return method.params.indexOf(param);
+        }
+
+        // Each class (including enclosed inner classes) is visited separately.
+        // This flag is used to prevent from visiting inner classes.
+        private boolean isInClass = false;
+
+        @Override
+        public void visitClassDef(JCClassDecl tree) {
+            if (isInClass)
+                return;
+            isInClass = true;
+            if (sigOnly) {
+                scan(tree.mods);
+                scan(tree.typarams);
+                scan(tree.extending);
+                scan(tree.implementing);
+            }
+            scan(tree.defs);
+        }
+
+        /**
+         * Resolve declaration vs. type annotations in methods and
+         * then determine the positions.
+         */
+        @Override
+        public void visitMethodDef(final JCMethodDecl tree) {
+            if (tree.sym == null) {
+                // Something most be wrong, e.g. a class not found.
+                // Quietly ignore. (See test FailOver15.java)
+                return;
+            }
+            if (sigOnly) {
+                {
+                    TypeAnnotationPosition pos = new TypeAnnotationPosition();
+                    pos.type = TargetType.METHOD_RETURN;
+                    if (tree.sym.isConstructor()) {
+                        pos.pos = tree.pos;
+                        // Use null to mark that the annotations go with the symbol.
+                        separateAnnotationsKinds(tree, null, tree.sym, pos);
+                    } else {
+                        pos.pos = tree.restype.pos;
+                        separateAnnotationsKinds(tree.restype, tree.sym.type.getReturnType(),
+                                tree.sym, pos);
+                    }
+                }
+                if (tree.recvparam != null && tree.recvparam.sym != null) {
+                    // TODO: make sure there are no declaration annotations.
+                    TypeAnnotationPosition pos = new TypeAnnotationPosition();
+                    pos.type = TargetType.METHOD_RECEIVER;
+                    pos.pos = tree.recvparam.vartype.pos;
+                    separateAnnotationsKinds(tree.recvparam.vartype, tree.recvparam.sym.type,
+                            tree.recvparam.sym, pos);
+                }
+                int i = 0;
+                for (JCVariableDecl param : tree.params) {
+                    TypeAnnotationPosition pos = new TypeAnnotationPosition();
+                    pos.type = TargetType.METHOD_FORMAL_PARAMETER;
+                    pos.parameter_index = i;
+                    pos.pos = param.vartype.pos;
+                    separateAnnotationsKinds(param.vartype, param.sym.type, param.sym, pos);
+                    ++i;
+                }
+            }
+
+            push(tree);
+            // super.visitMethodDef(tree);
+            if (sigOnly) {
+                scan(tree.mods);
+                scan(tree.restype);
+                scan(tree.typarams);
+                scan(tree.recvparam);
+                scan(tree.params);
+                scan(tree.thrown);
+            } else {
+                scan(tree.defaultValue);
+                scan(tree.body);
+            }
+            pop();
+        }
+
+        /**
+         * Resolve declaration vs. type annotations in variable declarations and
+         * then determine the positions.
+         */
+        @Override
+        public void visitVarDef(final JCVariableDecl tree) {
+            if (tree.sym == null) {
+                // Something is wrong already. Quietly ignore.
+            } else if (tree.sym.getKind() == ElementKind.FIELD) {
+                if (sigOnly) {
+                    TypeAnnotationPosition pos = new TypeAnnotationPosition();
+                    pos.type = TargetType.FIELD;
+                    pos.pos = tree.pos;
+                    separateAnnotationsKinds(tree.vartype, tree.sym.type, tree.sym, pos);
+                }
+            } else if (tree.sym.getKind() == ElementKind.LOCAL_VARIABLE) {
+                TypeAnnotationPosition pos = new TypeAnnotationPosition();
+                pos.type = TargetType.LOCAL_VARIABLE;
+                pos.pos = tree.pos;
+                separateAnnotationsKinds(tree.vartype, tree.sym.type, tree.sym, pos);
+            } else if (tree.sym.getKind() == ElementKind.EXCEPTION_PARAMETER) {
+                // System.out.println("Found exception param: " + tree);
+                TypeAnnotationPosition pos = new TypeAnnotationPosition();
+                pos.type = TargetType.EXCEPTION_PARAMETER;
+                pos.pos = tree.pos;
+                separateAnnotationsKinds(tree.vartype, tree.sym.type, tree.sym, pos);
+            } else if (tree.sym.getKind() == ElementKind.RESOURCE_VARIABLE) {
+                TypeAnnotationPosition pos = new TypeAnnotationPosition();
+                pos.type = TargetType.RESOURCE_VARIABLE;
+                pos.pos = tree.pos;
+                separateAnnotationsKinds(tree.vartype, tree.sym.type, tree.sym, pos);
+            } else {
+                // There is nothing else in a variable declaration that needs separation.
+                // System.out.println("We found a: " + tree);
+            }
+
+            push(tree);
+            // super.visitVarDef(tree);
+            scan(tree.mods);
+            scan(tree.vartype);
+            if (!sigOnly) {
+                scan(tree.init);
+            }
+            pop();
+        }
+
+        @Override
+        public void visitBlock(JCBlock tree) {
+            // Do not descend into top-level blocks when only interested
+            // in the signature.
+            if (!sigOnly) {
+                scan(tree.stats);
+            }
+        }
+
+        @Override
+        public void visitAnnotatedType(JCAnnotatedType tree) {
+            push(tree);
+            findPosition(tree, tree, tree.annotations);
+            pop();
+            super.visitAnnotatedType(tree);
+        }
+
+        @Override
+        public void visitTypeParameter(JCTypeParameter tree) {
+            findPosition(tree, peek2(), tree.annotations);
+            super.visitTypeParameter(tree);
+        }
+
+        @Override
+        public void visitNewArray(JCNewArray tree) {
+            findPosition(tree, tree, tree.annotations);
+            int dimAnnosCount = tree.dimAnnotations.size();
+            ListBuffer<TypePathEntry> depth = ListBuffer.lb();
+
+            // handle annotations associated with dimensions
+            for (int i = 0; i < dimAnnosCount; ++i) {
+                TypeAnnotationPosition p = new TypeAnnotationPosition();
+                p.pos = tree.pos;
+                p.type = TargetType.NEW;
+                if (i != 0) {
+                    depth = depth.append(TypePathEntry.ARRAY);
+                    p.location = p.location.appendList(depth.toList());
+                }
+
+                setTypeAnnotationPos(tree.dimAnnotations.get(i), p);
+            }
+
+            // handle "free" annotations
+            // int i = dimAnnosCount == 0 ? 0 : dimAnnosCount - 1;
+            // TODO: is depth.size == i here?
+            JCExpression elemType = tree.elemtype;
+            while (elemType != null) {
+                if (elemType.hasTag(JCTree.Tag.ANNOTATED_TYPE)) {
+                    JCAnnotatedType at = (JCAnnotatedType)elemType;
+                    TypeAnnotationPosition p = new TypeAnnotationPosition();
+                    p.type = TargetType.NEW;
+                    p.pos = tree.pos;
+                    p.location = p.location.appendList(depth.toList());
+                    setTypeAnnotationPos(at.annotations, p);
+                    elemType = at.underlyingType;
+                } else if (elemType.hasTag(JCTree.Tag.TYPEARRAY)) {
+                    depth = depth.append(TypePathEntry.ARRAY);
+                    elemType = ((JCArrayTypeTree)elemType).elemtype;
+                } else {
+                    break;
+                }
+            }
+            scan(tree.elems);
+        }
+
+        private void findPosition(JCTree tree, JCTree frame, List<JCAnnotation> annotations) {
+            if (!annotations.isEmpty()) {
+                /*
+                System.out.println("Finding pos for: " + annotations);
+                System.out.println("    tree: " + tree);
+                System.out.println("    frame: " + frame);
+                */
+                TypeAnnotationPosition p = new TypeAnnotationPosition();
+                resolveFrame(tree, frame, frames.toList(), p);
+                setTypeAnnotationPos(annotations, p);
+            }
+        }
+
+        private static void setTypeAnnotationPos(List<JCAnnotation> annotations,
+                TypeAnnotationPosition position) {
+            for (JCAnnotation anno : annotations) {
+                ((Attribute.TypeCompound) anno.attribute).position = position;
+            }
+        }
+    }
+}