/*

  * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package com.sun.tools.javac.comp;

 import com.sun.tools.javac.code.*;

 import com.sun.tools.javac.code.Attribute.Compound;

 import com.sun.tools.javac.code.Attribute.TypeCompound;

 import com.sun.tools.javac.code.Scope.WriteableScope;

 import com.sun.tools.javac.code.Symbol.*;

 import com.sun.tools.javac.code.TypeMetadata.Entry.Kind;

 import com.sun.tools.javac.resources.CompilerProperties.Errors;

 import com.sun.tools.javac.tree.JCTree;

 import com.sun.tools.javac.tree.JCTree.*;

 import com.sun.tools.javac.tree.TreeInfo;

 import com.sun.tools.javac.tree.TreeMaker;

 import com.sun.tools.javac.tree.TreeScanner;

 import com.sun.tools.javac.util.*;

 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticPosition;

 import com.sun.tools.javac.util.List;

 import javax.tools.JavaFileObject;

 import java.util.*;

 import static com.sun.tools.javac.code.Flags.SYNTHETIC;

 import static com.sun.tools.javac.code.Kinds.Kind.MDL;

 import static com.sun.tools.javac.code.Kinds.Kind.MTH;

 import static com.sun.tools.javac.code.Kinds.Kind.PCK;

 import static com.sun.tools.javac.code.Kinds.Kind.VAR;

 import static com.sun.tools.javac.code.Scope.LookupKind.NON_RECURSIVE;

 import static com.sun.tools.javac.code.TypeTag.ARRAY;

 import static com.sun.tools.javac.code.TypeTag.CLASS;

 import static com.sun.tools.javac.tree.JCTree.Tag.ANNOTATION;

 import static com.sun.tools.javac.tree.JCTree.Tag.ASSIGN;

 import static com.sun.tools.javac.tree.JCTree.Tag.IDENT;

 import static com.sun.tools.javac.tree.JCTree.Tag.NEWARRAY;

 import com.sun.tools.javac.util.JCDiagnostic.DiagnosticFlag;

 /** Enter annotations onto symbols and types (and trees).

  *

  *  This is also a pseudo stage in the compiler taking care of scheduling when annotations are

  *  entered.

  *

  *  <p><b>This is NOT part of any supported API.

  *  If you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  */

 public class Annotate {

     protected static final Context.Key<Annotate> annotateKey = new Context.Key<>();

     public static Annotate instance(Context context) {

         Annotate instance = context.get(annotateKey);

         if (instance == null)

             instance = new Annotate(context);

         return instance;

     }

     private final Attr attr;

     private final Check chk;

     private final ConstFold cfolder;

     private final DeferredLintHandler deferredLintHandler;

     private final Enter enter;

     private final Lint lint;

     private final Log log;

     private final Names names;

     private final Resolve resolve;

     private final TreeMaker make;

     private final Symtab syms;

     private final TypeEnvs typeEnvs;

     private final Types types;

     private final Attribute theUnfinishedDefaultValue;

     private final boolean allowRepeatedAnnos;

     private final String sourceName;

     protected Annotate(Context context) {

         context.put(annotateKey, this);

         attr = Attr.instance(context);

         chk = Check.instance(context);

         cfolder = ConstFold.instance(context);

         deferredLintHandler = DeferredLintHandler.instance(context);

         enter = Enter.instance(context);

         log = Log.instance(context);

         lint = Lint.instance(context);

         make = TreeMaker.instance(context);

         names = Names.instance(context);

         resolve = Resolve.instance(context);

         syms = Symtab.instance(context);

         typeEnvs = TypeEnvs.instance(context);

         types = Types.instance(context);

         theUnfinishedDefaultValue =  new Attribute.Error(syms.errType);

         Source source = Source.instance(context);

         allowRepeatedAnnos = source.allowRepeatedAnnotations();

         sourceName = source.name;

         blockCount = 1;

     }

     /** Semaphore to delay annotation processing */

     private int blockCount = 0;

     /** Called when annotations processing needs to be postponed. */

     public void blockAnnotations() {

         blockCount++;

     }

     /** Called when annotation processing can be resumed. */

     public void unblockAnnotations() {

         blockCount--;

         if (blockCount == 0)

             flush();

     }

     /** Variant which allows for a delayed flush of annotations.

      * Needed by ClassReader */

     public void unblockAnnotationsNoFlush() {

         blockCount--;

     }

     /** are we blocking annotation processing? */

     public boolean annotationsBlocked() {return blockCount > 0; }

     public void enterDone() {

         unblockAnnotations();

     }

     public List<TypeCompound> fromAnnotations(List<JCAnnotation> annotations) {

         if (annotations.isEmpty()) {

             return List.nil();

         }

         ListBuffer<TypeCompound> buf = new ListBuffer<>();

         for (JCAnnotation anno : annotations) {

             Assert.checkNonNull(anno.attribute);

             buf.append((TypeCompound) anno.attribute);

         }

         return buf.toList();

     }

     /** Annotate (used for everything else) */

     public void normal(Runnable r) {

         q.append(r);

     }

     /** Validate, triggers after 'normal' */

     public void validate(Runnable a) {

         validateQ.append(a);

     }

     /** Flush all annotation queues */

     public void flush() {

         if (annotationsBlocked()) return;

         if (isFlushing()) return;

         startFlushing();

         try {

             while (q.nonEmpty()) {

                 q.next().run();

             }

             while (typesQ.nonEmpty()) {

                 typesQ.next().run();

             }

             while (afterTypesQ.nonEmpty()) {

                 afterTypesQ.next().run();

             }

             while (validateQ.nonEmpty()) {

                 validateQ.next().run();

             }

         } finally {

             doneFlushing();

         }

     }

     private ListBuffer<Runnable> q = new ListBuffer<>();

     private ListBuffer<Runnable> validateQ = new ListBuffer<>();

     private int flushCount = 0;

     public boolean isFlushing() { return flushCount > 0; }

     private void startFlushing() { flushCount++; }

     private void doneFlushing() { flushCount--; }

     ListBuffer<Runnable> typesQ = new ListBuffer<>();

     ListBuffer<Runnable> afterTypesQ = new ListBuffer<>();

     public void typeAnnotation(Runnable a) {

         typesQ.append(a);

     }

     public void afterTypes(Runnable a) {

         afterTypesQ.append(a);

     }

     /**

      * Queue annotations for later attribution and entering. This is probably the method you are looking for.

      *

      * @param annotations the list of JCAnnotations to attribute and enter

      * @param localEnv    the enclosing env

      * @param s           ths Symbol on which to enter the annotations

      * @param deferPos    report errors here

      */

     public void annotateLater(List<JCAnnotation> annotations, Env<AttrContext> localEnv,

             Symbol s, DiagnosticPosition deferPos)

     {

         if (annotations.isEmpty()) {

             return;

         }

         s.resetAnnotations(); // mark Annotations as incomplete for now

         normal(() -> {

             // Packages are unusual, in that they are the only type of declaration that can legally appear

             // more than once in a compilation, and in all cases refer to the same underlying symbol.

             // This means they are the only kind of declaration that syntactically may have multiple sets

             // of annotations, each on a different package declaration, even though that is ultimately

             // forbidden by JLS 8 section 7.4.

             // The corollary here is that all of the annotations on a package symbol may have already

             // been handled, meaning that the set of annotations pending completion is now empty.

             Assert.check(s.kind == PCK || s.annotationsPendingCompletion());

             JavaFileObject prev = log.useSource(localEnv.toplevel.sourcefile);

             DiagnosticPosition prevLintPos =

                     deferPos != null

                             ? deferredLintHandler.setPos(deferPos)

                             : deferredLintHandler.immediate();

             Lint prevLint = deferPos != null ? null : chk.setLint(lint);

             try {

                 if (s.hasAnnotations() && annotations.nonEmpty())

                     log.error(annotations.head.pos, "already.annotated", Kinds.kindName(s), s);

                 Assert.checkNonNull(s, "Symbol argument to actualEnterAnnotations is null");

                 // false is passed as fifth parameter since annotateLater is

                 // never called for a type parameter

                 annotateNow(s, annotations, localEnv, false, false);

             } finally {

                 if (prevLint != null)

                     chk.setLint(prevLint);

                 deferredLintHandler.setPos(prevLintPos);

                 log.useSource(prev);

             }

         });

         validate(() -> { //validate annotations

             JavaFileObject prev = log.useSource(localEnv.toplevel.sourcefile);

             try {

                 chk.validateAnnotations(annotations, s);

             } finally {

                 log.useSource(prev);

             }

         });

     }

     /** Queue processing of an attribute default value. */

     public void annotateDefaultValueLater(JCExpression defaultValue, Env<AttrContext> localEnv,

             MethodSymbol m, DiagnosticPosition deferPos)

     {

         normal(() -> {

             JavaFileObject prev = log.useSource(localEnv.toplevel.sourcefile);

             DiagnosticPosition prevLintPos = deferredLintHandler.setPos(deferPos);

             try {

                 enterDefaultValue(defaultValue, localEnv, m);

             } finally {

                 deferredLintHandler.setPos(prevLintPos);

                 log.useSource(prev);

             }

         });

         validate(() -> { //validate annotations

             JavaFileObject prev = log.useSource(localEnv.toplevel.sourcefile);

             try {

                 // if default value is an annotation, check it is a well-formed

                 // annotation value (e.g. no duplicate values, no missing values, etc.)

                 chk.validateAnnotationTree(defaultValue);

             } finally {

                 log.useSource(prev);

             }

         });

     }

     /** Enter a default value for an annotation element. */

     private void enterDefaultValue(JCExpression defaultValue,

             Env<AttrContext> localEnv, MethodSymbol m) {

         m.defaultValue = attributeAnnotationValue(m.type.getReturnType(), defaultValue, localEnv);

     }

     /**

      * Gather up annotations into a map from type symbols to lists of Compound attributes,

      * then continue on with repeating annotations processing.

      */

     private <T extends Attribute.Compound> void annotateNow(Symbol toAnnotate,

             List<JCAnnotation> withAnnotations, Env<AttrContext> env, boolean typeAnnotations,

             boolean isTypeParam)

     {

         Map<TypeSymbol, ListBuffer<T>> annotated = new LinkedHashMap<>();

         Map<T, DiagnosticPosition> pos = new HashMap<>();

         for (List<JCAnnotation> al = withAnnotations; !al.isEmpty(); al = al.tail) {

             JCAnnotation a = al.head;

             T c;

             if (typeAnnotations) {

                 @SuppressWarnings("unchecked")

                 T tmp = (T)attributeTypeAnnotation(a, syms.annotationType, env);

                 c = tmp;

             } else {

                 @SuppressWarnings("unchecked")

                 T tmp = (T)attributeAnnotation(a, syms.annotationType, env);

                 c = tmp;

             }

             Assert.checkNonNull(c, "Failed to create annotation");

             if (annotated.containsKey(a.type.tsym)) {

                 if (!allowRepeatedAnnos) {

                     log.error(DiagnosticFlag.SOURCE_LEVEL, a.pos(), "repeatable.annotations.not.supported.in.source", sourceName);

                 }

                 ListBuffer<T> l = annotated.get(a.type.tsym);

                 l = l.append(c);

                 annotated.put(a.type.tsym, l);

                 pos.put(c, a.pos());

             } else {

                 annotated.put(a.type.tsym, ListBuffer.of(c));

                 pos.put(c, a.pos());

             }

             // Note: @Deprecated has no effect on local variables and parameters

             if (!c.type.isErroneous()

                     && (toAnnotate.kind == MDL || toAnnotate.owner.kind != MTH)

                     && types.isSameType(c.type, syms.deprecatedType)) {

                 toAnnotate.flags_field |= (Flags.DEPRECATED | Flags.DEPRECATED_ANNOTATION);

                 Attribute fr = c.member(names.forRemoval);

                 if (fr instanceof Attribute.Constant) {

                     Attribute.Constant v = (Attribute.Constant) fr;

                     if (v.type == syms.booleanType && ((Integer) v.value) != 0) {

                         toAnnotate.flags_field |= Flags.DEPRECATED_REMOVAL;

                     }

                 }

             }

         }

         List<T> buf = List.nil();

         for (ListBuffer<T> lb : annotated.values()) {

             if (lb.size() == 1) {

                 buf = buf.prepend(lb.first());

             } else {

                 AnnotationContext<T> ctx = new AnnotationContext<>(env, annotated, pos, typeAnnotations);

                 T res = makeContainerAnnotation(lb.toList(), ctx, toAnnotate, isTypeParam);

                 if (res != null)

                     buf = buf.prepend(res);

             }

         }

         if (typeAnnotations) {

             @SuppressWarnings("unchecked")

             List<TypeCompound> attrs = (List<TypeCompound>)buf.reverse();

             toAnnotate.appendUniqueTypeAttributes(attrs);

         } else {

             @SuppressWarnings("unchecked")

             List<Attribute.Compound> attrs =  (List<Attribute.Compound>)buf.reverse();

             toAnnotate.resetAnnotations();

             toAnnotate.setDeclarationAttributes(attrs);

         }

     }

     /**

      * Attribute and store a semantic representation of the annotation tree {@code tree} into the

      * tree.attribute field.

      *

      * @param tree the tree representing an annotation

      * @param expectedAnnotationType the expected (super)type of the annotation

      * @param env the current env in where the annotation instance is found

      */

     public Attribute.Compound attributeAnnotation(JCAnnotation tree, Type expectedAnnotationType,

                                                   Env<AttrContext> env)

     {

         // The attribute might have been entered if it is Target or Repetable

         // Because TreeCopier does not copy type, redo this if type is null

         if (tree.attribute != null && tree.type != null)

             return tree.attribute;

         List<Pair<MethodSymbol, Attribute>> elems = attributeAnnotationValues(tree, expectedAnnotationType, env);

         Attribute.Compound ac = new Attribute.Compound(tree.type, elems);

         return tree.attribute = ac;

     }

     /** Attribute and store a semantic representation of the type annotation tree {@code tree} into

      * the tree.attribute field.

      *

      * @param a the tree representing an annotation

      * @param expectedAnnotationType the expected (super)type of the annotation

      * @param env the the current env in where the annotation instance is found

      */

     public Attribute.TypeCompound attributeTypeAnnotation(JCAnnotation a, Type expectedAnnotationType,

                                                           Env<AttrContext> env)

     {

         // The attribute might have been entered if it is Target or Repetable

         // Because TreeCopier does not copy type, redo this if type is null

         if (a.attribute == null || a.type == null || !(a.attribute instanceof Attribute.TypeCompound)) {

             // Create a new TypeCompound

             List<Pair<MethodSymbol,Attribute>> elems =

                     attributeAnnotationValues(a, expectedAnnotationType, env);

             Attribute.TypeCompound tc =

                     new Attribute.TypeCompound(a.type, elems, TypeAnnotationPosition.unknown);

             a.attribute = tc;

             return tc;

         } else {

             // Use an existing TypeCompound

             return (Attribute.TypeCompound)a.attribute;

         }

     }

     /**

      *  Attribute annotation elements creating a list of pairs of the Symbol representing that

      *  element and the value of that element as an Attribute. */

     private List<Pair<MethodSymbol, Attribute>> attributeAnnotationValues(JCAnnotation a,

             Type expected, Env<AttrContext> env)

     {

         // The annotation might have had its type attributed (but not

         // checked) by attr.attribAnnotationTypes during MemberEnter,

         // in which case we do not need to do it again.

         Type at = (a.annotationType.type != null ?

                 a.annotationType.type : attr.attribType(a.annotationType, env));

         a.type = chk.checkType(a.annotationType.pos(), at, expected);

         boolean isError = a.type.isErroneous();

         if (!a.type.tsym.isAnnotationType() && !isError) {

             log.error(a.annotationType.pos(),

                     "not.annotation.type", a.type.toString());

             isError = true;

         }

         // List of name=value pairs (or implicit "value=" if size 1)

         List<JCExpression> args = a.args;

         boolean elidedValue = false;

         // special case: elided "value=" assumed

         if (args.length() == 1 && !args.head.hasTag(ASSIGN)) {

             args.head = make.at(Position.NOPOS).

                     Assign(make.Ident(names.value), args.head);

             elidedValue = true;

         }

         ListBuffer<Pair<MethodSymbol,Attribute>> buf = new ListBuffer<>();

         for (List<JCExpression> tl = args; tl.nonEmpty(); tl = tl.tail) {

             Pair<MethodSymbol, Attribute> p = attributeAnnotationNameValuePair(tl.head, a.type, isError, env, elidedValue);

             if (p != null && !p.fst.type.isErroneous())

                 buf.append(p);

         }

         return buf.toList();

     }

     // where

     private Pair<MethodSymbol, Attribute> attributeAnnotationNameValuePair(JCExpression nameValuePair,

             Type thisAnnotationType, boolean badAnnotation, Env<AttrContext> env, boolean elidedValue)

     {

         if (!nameValuePair.hasTag(ASSIGN)) {

             log.error(nameValuePair.pos(), "annotation.value.must.be.name.value");

             attributeAnnotationValue(nameValuePair.type = syms.errType, nameValuePair, env);

             return null;

         }

         JCAssign assign = (JCAssign)nameValuePair;

         if (!assign.lhs.hasTag(IDENT)) {

             log.error(nameValuePair.pos(), "annotation.value.must.be.name.value");

             attributeAnnotationValue(nameValuePair.type = syms.errType, nameValuePair, env);

             return null;

         }

         // Resolve element to MethodSym

         JCIdent left = (JCIdent)assign.lhs;

         Symbol method = resolve.resolveQualifiedMethod(elidedValue ? assign.rhs.pos() : left.pos(),

                 env, thisAnnotationType,

                 left.name, List.nil(), null);

         left.sym = method;

         left.type = method.type;

         if (method.owner != thisAnnotationType.tsym && !badAnnotation)

             log.error(left.pos(), "no.annotation.member", left.name, thisAnnotationType);

         Type resultType = method.type.getReturnType();

         // Compute value part

         Attribute value = attributeAnnotationValue(resultType, assign.rhs, env);

         nameValuePair.type = resultType;

         return method.type.isErroneous() ? null : new Pair<>((MethodSymbol)method, value);

     }

     /** Attribute an annotation element value */

     private Attribute attributeAnnotationValue(Type expectedElementType, JCExpression tree,

             Env<AttrContext> env)

     {

         //first, try completing the symbol for the annotation value - if acompletion

         //error is thrown, we should recover gracefully, and display an

         //ordinary resolution diagnostic.

         try {

             expectedElementType.tsym.complete();

         } catch(CompletionFailure e) {

             log.error(tree.pos(), "cant.resolve", Kinds.kindName(e.sym), e.sym);

             expectedElementType = syms.errType;

         }

         if (expectedElementType.hasTag(ARRAY)) {

             return getAnnotationArrayValue(expectedElementType, tree, env);

         }

         //error recovery

         if (tree.hasTag(NEWARRAY)) {

             if (!expectedElementType.isErroneous())

                 log.error(tree.pos(), "annotation.value.not.allowable.type");

             JCNewArray na = (JCNewArray)tree;

             if (na.elemtype != null) {

                 log.error(na.elemtype.pos(), "new.not.allowed.in.annotation");

             }

             for (List<JCExpression> l = na.elems; l.nonEmpty(); l=l.tail) {

                 attributeAnnotationValue(syms.errType,

                         l.head,

                         env);

             }

             return new Attribute.Error(syms.errType);

         }

         if (expectedElementType.tsym.isAnnotationType()) {

             if (tree.hasTag(ANNOTATION)) {

                 return attributeAnnotation((JCAnnotation)tree, expectedElementType, env);

             } else {

                 log.error(tree.pos(), "annotation.value.must.be.annotation");

                 expectedElementType = syms.errType;

             }

         }

         //error recovery

         if (tree.hasTag(ANNOTATION)) {

             if (!expectedElementType.isErroneous())

                 log.error(tree.pos(), "annotation.not.valid.for.type", expectedElementType);

             attributeAnnotation((JCAnnotation)tree, syms.errType, env);

             return new Attribute.Error(((JCAnnotation)tree).annotationType.type);

         }

         if (expectedElementType.isPrimitive() ||

                 (types.isSameType(expectedElementType, syms.stringType) && !expectedElementType.hasTag(TypeTag.ERROR))) {

             return getAnnotationPrimitiveValue(expectedElementType, tree, env);

         }

         if (expectedElementType.tsym == syms.classType.tsym) {

             return getAnnotationClassValue(expectedElementType, tree, env);

         }

         if (expectedElementType.hasTag(CLASS) &&

                 (expectedElementType.tsym.flags() & Flags.ENUM) != 0) {

             return getAnnotationEnumValue(expectedElementType, tree, env);

         }

         //error recovery:

         if (!expectedElementType.isErroneous())

             log.error(tree.pos(), "annotation.value.not.allowable.type");

         return new Attribute.Error(attr.attribExpr(tree, env, expectedElementType));

     }

     private Attribute getAnnotationEnumValue(Type expectedElementType, JCExpression tree, Env<AttrContext> env) {

         Type result = attr.attribExpr(tree, env, expectedElementType);

         Symbol sym = TreeInfo.symbol(tree);

         if (sym == null ||

                 TreeInfo.nonstaticSelect(tree) ||

                 sym.kind != VAR ||

                 (sym.flags() & Flags.ENUM) == 0) {

             log.error(tree.pos(), "enum.annotation.must.be.enum.constant");

             return new Attribute.Error(result.getOriginalType());

         }

         VarSymbol enumerator = (VarSymbol) sym;

         return new Attribute.Enum(expectedElementType, enumerator);

     }

     private Attribute getAnnotationClassValue(Type expectedElementType, JCExpression tree, Env<AttrContext> env) {

         Type result = attr.attribExpr(tree, env, expectedElementType);

         if (result.isErroneous()) {

             // Does it look like an unresolved class literal?

             if (TreeInfo.name(tree) == names._class &&

                     ((JCFieldAccess) tree).selected.type.isErroneous()) {

                 Name n = (((JCFieldAccess) tree).selected).type.tsym.flatName();

                 return new Attribute.UnresolvedClass(expectedElementType,

                         types.createErrorType(n,

                                 syms.unknownSymbol, syms.classType));

             } else {

                 return new Attribute.Error(result.getOriginalType());

             }

         }

         // Class literals look like field accesses of a field named class

         // at the tree level

         if (TreeInfo.name(tree) != names._class) {

             log.error(tree.pos(), "annotation.value.must.be.class.literal");

             return new Attribute.Error(syms.errType);

         }

         return new Attribute.Class(types,

                 (((JCFieldAccess) tree).selected).type);

     }

     private Attribute getAnnotationPrimitiveValue(Type expectedElementType, JCExpression tree, Env<AttrContext> env) {

         Type result = attr.attribExpr(tree, env, expectedElementType);

         if (result.isErroneous())

             return new Attribute.Error(result.getOriginalType());

         if (result.constValue() == null) {

             log.error(tree.pos(), "attribute.value.must.be.constant");

             return new Attribute.Error(expectedElementType);

         }

         result = cfolder.coerce(result, expectedElementType);

         return new Attribute.Constant(expectedElementType, result.constValue());

     }

     private Attribute getAnnotationArrayValue(Type expectedElementType, JCExpression tree, Env<AttrContext> env) {

         // Special case, implicit array

         if (!tree.hasTag(NEWARRAY)) {

             tree = make.at(tree.pos).

                     NewArray(null, List.nil(), List.of(tree));

         }

         JCNewArray na = (JCNewArray)tree;

         if (na.elemtype != null) {

             log.error(na.elemtype.pos(), "new.not.allowed.in.annotation");

         }

         ListBuffer<Attribute> buf = new ListBuffer<>();

         if (na.elems != null) {

             for (List<JCExpression> l = na.elems; l.nonEmpty(); l=l.tail) {

                 buf.append(attributeAnnotationValue(types.elemtype(expectedElementType),

                         l.head,

                         env));

             }

         }

         na.type = expectedElementType;

         return new Attribute.

                 Array(expectedElementType, buf.toArray(new Attribute[buf.length()]));

     }

     /* *********************************

      * Support for repeating annotations

      ***********************************/

     /**

      * This context contains all the information needed to synthesize new

      * annotations trees for repeating annotations.

      */

     private class AnnotationContext<T extends Attribute.Compound> {

         public final Env<AttrContext> env;

         public final Map<Symbol.TypeSymbol, ListBuffer<T>> annotated;

         public final Map<T, JCDiagnostic.DiagnosticPosition> pos;

         public final boolean isTypeCompound;

         public AnnotationContext(Env<AttrContext> env,

                                  Map<Symbol.TypeSymbol, ListBuffer<T>> annotated,

                                  Map<T, JCDiagnostic.DiagnosticPosition> pos,

                                  boolean isTypeCompound) {

             Assert.checkNonNull(env);

             Assert.checkNonNull(annotated);

             Assert.checkNonNull(pos);

             this.env = env;

             this.annotated = annotated;

             this.pos = pos;

             this.isTypeCompound = isTypeCompound;

         }

     }

     /* Process repeated annotations. This method returns the

      * synthesized container annotation or null IFF all repeating

      * annotation are invalid.  This method reports errors/warnings.

      */

     private <T extends Attribute.Compound> T processRepeatedAnnotations(List<T> annotations,

             AnnotationContext<T> ctx, Symbol on, boolean isTypeParam)

     {

         T firstOccurrence = annotations.head;

         List<Attribute> repeated = List.nil();

         Type origAnnoType = null;

         Type arrayOfOrigAnnoType = null;

         Type targetContainerType = null;

         MethodSymbol containerValueSymbol = null;

         Assert.check(!annotations.isEmpty() && !annotations.tail.isEmpty()); // i.e. size() > 1

         int count = 0;

         for (List<T> al = annotations; !al.isEmpty(); al = al.tail) {

             count++;

             // There must be more than a single anno in the annotation list

             Assert.check(count > 1 || !al.tail.isEmpty());

             T currentAnno = al.head;

             origAnnoType = currentAnno.type;

             if (arrayOfOrigAnnoType == null) {

                 arrayOfOrigAnnoType = types.makeArrayType(origAnnoType);

             }

             // Only report errors if this isn't the first occurrence I.E. count > 1

             boolean reportError = count > 1;

             Type currentContainerType = getContainingType(currentAnno, ctx.pos.get(currentAnno), reportError);

             if (currentContainerType == null) {

                 continue;

             }

             // Assert that the target Container is == for all repeated

             // annos of the same annotation type, the types should

             // come from the same Symbol, i.e. be '=='

             Assert.check(targetContainerType == null || currentContainerType == targetContainerType);

             targetContainerType = currentContainerType;

             containerValueSymbol = validateContainer(targetContainerType, origAnnoType, ctx.pos.get(currentAnno));

             if (containerValueSymbol == null) { // Check of CA type failed

                 // errors are already reported

                 continue;

             }

             repeated = repeated.prepend(currentAnno);

         }

         if (!repeated.isEmpty() && targetContainerType == null) {

             log.error(ctx.pos.get(annotations.head), "duplicate.annotation.invalid.repeated", origAnnoType);

             return null;

         }

         if (!repeated.isEmpty()) {

             repeated = repeated.reverse();

             DiagnosticPosition pos = ctx.pos.get(firstOccurrence);

             TreeMaker m = make.at(pos);

             Pair<MethodSymbol, Attribute> p =

                     new Pair<MethodSymbol, Attribute>(containerValueSymbol,

                             new Attribute.Array(arrayOfOrigAnnoType, repeated));

             if (ctx.isTypeCompound) {

                 /* TODO: the following code would be cleaner:

                 Attribute.TypeCompound at = new Attribute.TypeCompound(targetContainerType, List.of(p),

                         ((Attribute.TypeCompound)annotations.head).position);

                 JCTypeAnnotation annoTree = m.TypeAnnotation(at);

                 at = attributeTypeAnnotation(annoTree, targetContainerType, ctx.env);

                 */

                 // However, we directly construct the TypeCompound to keep the

                 // direct relation to the contained TypeCompounds.

                 Attribute.TypeCompound at = new Attribute.TypeCompound(targetContainerType, List.of(p),

                         ((Attribute.TypeCompound)annotations.head).position);

                 JCAnnotation annoTree = m.TypeAnnotation(at);

                 if (!chk.validateAnnotationDeferErrors(annoTree))

                     log.error(annoTree.pos(), Errors.DuplicateAnnotationInvalidRepeated(origAnnoType));

                 if (!chk.isTypeAnnotation(annoTree, isTypeParam)) {

                     log.error(pos, isTypeParam ? Errors.InvalidRepeatableAnnotationNotApplicable(targetContainerType, on)

                                                : Errors.InvalidRepeatableAnnotationNotApplicableInContext(targetContainerType));

                 }

                 at.setSynthesized(true);

                 @SuppressWarnings("unchecked")

                 T x = (T) at;

                 return x;

             } else {

                 Attribute.Compound c = new Attribute.Compound(targetContainerType, List.of(p));

                 JCAnnotation annoTree = m.Annotation(c);

                 if (!chk.annotationApplicable(annoTree, on)) {

                     log.error(annoTree.pos(),

                               Errors.InvalidRepeatableAnnotationNotApplicable(targetContainerType, on));

                 }

                 if (!chk.validateAnnotationDeferErrors(annoTree))

                     log.error(annoTree.pos(), "duplicate.annotation.invalid.repeated", origAnnoType);

                 c = attributeAnnotation(annoTree, targetContainerType, ctx.env);

                 c.setSynthesized(true);

                 @SuppressWarnings("unchecked")

                 T x = (T) c;

                 return x;

             }

         } else {

             return null; // errors should have been reported elsewhere

         }

     }

     /**

      * Fetches the actual Type that should be the containing annotation.

      */

     private Type getContainingType(Attribute.Compound currentAnno,

                                    DiagnosticPosition pos,

                                    boolean reportError)

     {

         Type origAnnoType = currentAnno.type;

         TypeSymbol origAnnoDecl = origAnnoType.tsym;

         // Fetch the Repeatable annotation from the current

         // annotation's declaration, or null if it has none

         Attribute.Compound ca = origAnnoDecl.getAnnotationTypeMetadata().getRepeatable();

         if (ca == null) { // has no Repeatable annotation

             if (reportError)

                 log.error(pos, "duplicate.annotation.missing.container", origAnnoType, syms.repeatableType);

             return null;

         }

         return filterSame(extractContainingType(ca, pos, origAnnoDecl),

                 origAnnoType);

     }

     // returns null if t is same as 's', returns 't' otherwise

     private Type filterSame(Type t, Type s) {

         if (t == null || s == null) {

             return t;

         }

         return types.isSameType(t, s) ? null : t;

     }

     /** Extract the actual Type to be used for a containing annotation. */

     private Type extractContainingType(Attribute.Compound ca,

                                        DiagnosticPosition pos,

                                        TypeSymbol annoDecl)

     {

         // The next three checks check that the Repeatable annotation

         // on the declaration of the annotation type that is repeating is

         // valid.

         // Repeatable must have at least one element

         if (ca.values.isEmpty()) {

             log.error(pos, "invalid.repeatable.annotation", annoDecl);

             return null;

         }

         Pair<MethodSymbol,Attribute> p = ca.values.head;

         Name name = p.fst.name;

         if (name != names.value) { // should contain only one element, named "value"

             log.error(pos, "invalid.repeatable.annotation", annoDecl);

             return null;

         }

         if (!(p.snd instanceof Attribute.Class)) { // check that the value of "value" is an Attribute.Class

             log.error(pos, "invalid.repeatable.annotation", annoDecl);

             return null;

         }

         return ((Attribute.Class)p.snd).getValue();

     }

     /* Validate that the suggested targetContainerType Type is a valid

      * container type for repeated instances of originalAnnoType

      * annotations. Return null and report errors if this is not the

      * case, return the MethodSymbol of the value element in

      * targetContainerType if it is suitable (this is needed to

      * synthesize the container). */

     private MethodSymbol validateContainer(Type targetContainerType,

                                            Type originalAnnoType,

                                            DiagnosticPosition pos) {

         MethodSymbol containerValueSymbol = null;

         boolean fatalError = false;

         // Validate that there is a (and only 1) value method

         Scope scope = targetContainerType.tsym.members();

         int nr_value_elems = 0;

         boolean error = false;

         for(Symbol elm : scope.getSymbolsByName(names.value)) {

             nr_value_elems++;

             if (nr_value_elems == 1 &&

                     elm.kind == MTH) {

                 containerValueSymbol = (MethodSymbol)elm;

             } else {

                 error = true;

             }

         }

         if (error) {

             log.error(pos,

                     "invalid.repeatable.annotation.multiple.values",

                     targetContainerType,

                     nr_value_elems);

             return null;

         } else if (nr_value_elems == 0) {

             log.error(pos,

                     "invalid.repeatable.annotation.no.value",

                     targetContainerType);

             return null;

         }

         // validate that the 'value' element is a method

         // probably "impossible" to fail this

         if (containerValueSymbol.kind != MTH) {

             log.error(pos,

                     "invalid.repeatable.annotation.invalid.value",

                     targetContainerType);

             fatalError = true;

         }

         // validate that the 'value' element has the correct return type

         // i.e. array of original anno

         Type valueRetType = containerValueSymbol.type.getReturnType();

         Type expectedType = types.makeArrayType(originalAnnoType);

         if (!(types.isArray(valueRetType) &&

                 types.isSameType(expectedType, valueRetType))) {

             log.error(pos,

                     "invalid.repeatable.annotation.value.return",

                     targetContainerType,

                     valueRetType,

                     expectedType);

             fatalError = true;

         }

         return fatalError ? null : containerValueSymbol;

     }

     private <T extends Attribute.Compound> T makeContainerAnnotation(List<T> toBeReplaced,

             AnnotationContext<T> ctx, Symbol sym, boolean isTypeParam)

     {

         // Process repeated annotations

         T validRepeated =

                 processRepeatedAnnotations(toBeReplaced, ctx, sym, isTypeParam);

         if (validRepeated != null) {

             // Check that the container isn't manually

             // present along with repeated instances of

             // its contained annotation.

             ListBuffer<T> manualContainer = ctx.annotated.get(validRepeated.type.tsym);

             if (manualContainer != null) {

                 log.error(ctx.pos.get(manualContainer.first()),

                         "invalid.repeatable.annotation.repeated.and.container.present",

                         manualContainer.first().type.tsym);

             }

         }

         // A null return will delete the Placeholder

         return validRepeated;

     }

     /********************

      * Type annotations *

      ********************/

     /**

      * Attribute the list of annotations and enter them onto s.

      */

     public void enterTypeAnnotations(List<JCAnnotation> annotations, Env<AttrContext> env,

             Symbol s, DiagnosticPosition deferPos, boolean isTypeParam)

     {

         Assert.checkNonNull(s, "Symbol argument to actualEnterTypeAnnotations is nul/");

         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);

         DiagnosticPosition prevLintPos = null;

         if (deferPos != null) {

             prevLintPos = deferredLintHandler.setPos(deferPos);

         }

         try {

             annotateNow(s, annotations, env, true, isTypeParam);

         } finally {

             if (prevLintPos != null)

                 deferredLintHandler.setPos(prevLintPos);

             log.useSource(prev);

         }

     }

     /**

      * Enqueue tree for scanning of type annotations, attaching to the Symbol sym.

      */

     public void queueScanTreeAndTypeAnnotate(JCTree tree, Env<AttrContext> env, Symbol sym,

             DiagnosticPosition deferPos)

     {

         Assert.checkNonNull(sym);

         normal(() -> tree.accept(new TypeAnnotate(env, sym, deferPos)));

     }

     /**

      * Apply the annotations to the particular type.

      */

     public void annotateTypeSecondStage(JCTree tree, List<JCAnnotation> annotations, Type storeAt) {

         typeAnnotation(() -> {

             List<Attribute.TypeCompound> compounds = fromAnnotations(annotations);

             Assert.check(annotations.size() == compounds.size());

             storeAt.getMetadataOfKind(Kind.ANNOTATIONS).combine(new TypeMetadata.Annotations(compounds));

         });

     }

     /**

      * Apply the annotations to the particular type.

      */

     public void annotateTypeParameterSecondStage(JCTree tree, List<JCAnnotation> annotations) {

         typeAnnotation(() -> {

             List<Attribute.TypeCompound> compounds = fromAnnotations(annotations);

             Assert.check(annotations.size() == compounds.size());

         });

     }

     /**

      * We need to use a TreeScanner, because it is not enough to visit the top-level

      * annotations. We also need to visit type arguments, etc.

      */

     private class TypeAnnotate extends TreeScanner {

         private final Env<AttrContext> env;

         private final Symbol sym;

         private DiagnosticPosition deferPos;

         public TypeAnnotate(Env<AttrContext> env, Symbol sym, DiagnosticPosition deferPos) {

             this.env = env;

             this.sym = sym;

             this.deferPos = deferPos;

         }

         @Override

         public void visitAnnotatedType(JCAnnotatedType tree) {

             enterTypeAnnotations(tree.annotations, env, sym, deferPos, false);

             scan(tree.underlyingType);

         }

         @Override

         public void visitTypeParameter(JCTypeParameter tree) {

             enterTypeAnnotations(tree.annotations, env, sym, deferPos, true);

             scan(tree.bounds);

         }

         @Override

         public void visitNewArray(JCNewArray tree) {

             enterTypeAnnotations(tree.annotations, env, sym, deferPos, false);

             for (List<JCAnnotation> dimAnnos : tree.dimAnnotations)

                 enterTypeAnnotations(dimAnnos, env, sym, deferPos, false);

             scan(tree.elemtype);

             scan(tree.elems);

         }

         @Override

         public void visitMethodDef(JCMethodDecl tree) {

             scan(tree.mods);

             scan(tree.restype);

             scan(tree.typarams);

             scan(tree.recvparam);

             scan(tree.params);

             scan(tree.thrown);

             scan(tree.defaultValue);

             // Do not annotate the body, just the signature.

         }

         @Override

         public void visitVarDef(JCVariableDecl tree) {

             DiagnosticPosition prevPos = deferPos;

             deferPos = tree.pos();

             try {

                 if (sym != null && sym.kind == VAR) {

                     // Don't visit a parameter once when the sym is the method

                     // and once when the sym is the parameter.

                     scan(tree.mods);

                     scan(tree.vartype);

                 }

                 scan(tree.init);

             } finally {

                 deferPos = prevPos;

             }

         }

         @Override

         public void visitClassDef(JCClassDecl tree) {

             // We can only hit a classdef if it is declared within

             // a method. Ignore it - the class will be visited

             // separately later.

         }

         @Override

         public void visitNewClass(JCNewClass tree) {

             scan(tree.encl);

             scan(tree.typeargs);

             scan(tree.clazz);

             scan(tree.args);

             // the anonymous class instantiation if any will be visited separately.

         }

         @Override

         public void visitErroneous(JCErroneous tree) {

             scan(tree.errs);

         }

     }

     /*********************

      * Completer support *

      *********************/

     private AnnotationTypeCompleter theSourceCompleter = new AnnotationTypeCompleter() {

         @Override

         public void complete(ClassSymbol sym) throws CompletionFailure {

             Env<AttrContext> context = typeEnvs.get(sym);

             Annotate.this.attributeAnnotationType(context);

         }

     };

     /* Last stage completer to enter just enough annotations to have a prototype annotation type.

      * This currently means entering @Target and @Repetable.

      */

     public AnnotationTypeCompleter annotationTypeSourceCompleter() {

         return theSourceCompleter;

     }

     private void attributeAnnotationType(Env<AttrContext> env) {

         Assert.check(((JCClassDecl)env.tree).sym.isAnnotationType(),

                 "Trying to annotation type complete a non-annotation type");

         JavaFileObject prev = log.useSource(env.toplevel.sourcefile);

         try {

             JCClassDecl tree = (JCClassDecl)env.tree;

             AnnotationTypeVisitor v = new AnnotationTypeVisitor(attr, chk, syms, typeEnvs);

             v.scanAnnotationType(tree);

             tree.sym.getAnnotationTypeMetadata().setRepeatable(v.repeatable);

             tree.sym.getAnnotationTypeMetadata().setTarget(v.target);

         } finally {

             log.useSource(prev);

         }

     }

     public Attribute unfinishedDefaultValue() {

         return theUnfinishedDefaultValue;

     }

     public static interface AnnotationTypeCompleter {

         void complete(ClassSymbol sym) throws CompletionFailure;

     }

     /** Visitor to determine a prototype annotation type for a class declaring an annotation type.

      *

      *  <p><b>This is NOT part of any supported API.

      *  If you write code that depends on this, you do so at your own risk.

      *  This code and its internal interfaces are subject to change or

      *  deletion without notice.</b>

      */

     public class AnnotationTypeVisitor extends TreeScanner {

         private Env<AttrContext> env;

         private final Attr attr;

         private final Check check;

         private final Symtab tab;

         private final TypeEnvs typeEnvs;

         private Compound target;

         private Compound repeatable;

         public AnnotationTypeVisitor(Attr attr, Check check, Symtab tab, TypeEnvs typeEnvs) {

             this.attr = attr;

             this.check = check;

             this.tab = tab;

             this.typeEnvs = typeEnvs;

         }

         public Compound getRepeatable() {

             return repeatable;

         }

         public Compound getTarget() {

             return target;

         }

         public void scanAnnotationType(JCClassDecl decl) {

             visitClassDef(decl);

         }

         @Override

         public void visitClassDef(JCClassDecl tree) {

             Env<AttrContext> prevEnv = env;

             env = typeEnvs.get(tree.sym);

             try {

                 scan(tree.mods); // look for repeatable and target

                 // don't descend into body

             } finally {

                 env = prevEnv;

             }

         }

         @Override

         public void visitAnnotation(JCAnnotation tree) {

             Type t = tree.annotationType.type;

             if (t == null) {

                 t = attr.attribType(tree.annotationType, env);

                 tree.annotationType.type = t = check.checkType(tree.annotationType.pos(), t, tab.annotationType);

             }

             if (t == tab.annotationTargetType) {

                 target = Annotate.this.attributeAnnotation(tree, tab.annotationTargetType, env);

             } else if (t == tab.repeatableType) {

                 repeatable = Annotate.this.attributeAnnotation(tree, tab.repeatableType, env);

             }

         }

         @Override

         public void visitErroneous(JCErroneous tree) {

             scan(tree.errs);

         }

     }

     /** Represents the semantics of an Annotation Type.

      *

      *  <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 static class AnnotationTypeMetadata {

         final ClassSymbol metaDataFor;

         private Compound target;

         private Compound repeatable;

         private AnnotationTypeCompleter annotationTypeCompleter;

         public AnnotationTypeMetadata(ClassSymbol metaDataFor, AnnotationTypeCompleter annotationTypeCompleter) {

             this.metaDataFor = metaDataFor;

             this.annotationTypeCompleter = annotationTypeCompleter;

         }

         private void init() {

             // Make sure metaDataFor is member entered

             while (!metaDataFor.isCompleted())

                 metaDataFor.complete();

             if (annotationTypeCompleter != null) {

                 AnnotationTypeCompleter c = annotationTypeCompleter;

                 annotationTypeCompleter = null;

                 c.complete(metaDataFor);

             }

         }

         public void complete() {

             init();

         }

         public Compound getRepeatable() {

             init();

             return repeatable;

         }

         public void setRepeatable(Compound repeatable) {

             Assert.checkNull(this.repeatable);

             this.repeatable = repeatable;

         }

         public Compound getTarget() {

             init();

             return target;

         }

         public void setTarget(Compound target) {

             Assert.checkNull(this.target);

                 this.target = target;

         }

         public Set<MethodSymbol> getAnnotationElements() {

             init();

             Set<MethodSymbol> members = new LinkedHashSet<>();

             WriteableScope s = metaDataFor.members();

             Iterable<Symbol> ss = s.getSymbols(NON_RECURSIVE);

             for (Symbol sym : ss)

                 if (sym.kind == MTH &&

                         sym.name != sym.name.table.names.clinit &&

                         (sym.flags() & SYNTHETIC) == 0)

                     members.add((MethodSymbol)sym);

             return members;

         }

         public Set<MethodSymbol> getAnnotationElementsWithDefault() {

             init();

             Set<MethodSymbol> members = getAnnotationElements();

             Set<MethodSymbol> res = new LinkedHashSet<>();

             for (MethodSymbol m : members)

                 if (m.defaultValue != null)

                     res.add(m);

             return res;

         }

         @Override

         public String toString() {

             return "Annotation type for: " + metaDataFor;

         }

         public boolean isMetadataForAnnotationType() { return true; }

         public static AnnotationTypeMetadata notAnAnnotationType() {

             return NOT_AN_ANNOTATION_TYPE;

         }

         private static final AnnotationTypeMetadata NOT_AN_ANNOTATION_TYPE =

                 new AnnotationTypeMetadata(null, null) {

                     @Override

                     public void complete() {

                     } // do nothing

                     @Override

                     public String toString() {

                         return "Not an annotation type";

                     }

                     @Override

                     public Set<MethodSymbol> getAnnotationElements() {

                         return new LinkedHashSet<>(0);

                     }

                     @Override

                     public Set<MethodSymbol> getAnnotationElementsWithDefault() {

                         return new LinkedHashSet<>(0);

                     }

                     @Override

                     public boolean isMetadataForAnnotationType() {

                         return false;

                     }

                     @Override

                     public Compound getTarget() {

                         return null;

                     }

                     @Override

                     public Compound getRepeatable() {

                         return null;

                     }

                 };

     }

     public void newRound() {

         blockCount = 1;

     }

 }