content: /*
   * Copyright (c) 2012, 2021, 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 openjdk.tools.javac.code;
  
  
  import openjdk.tools.javac.code.Attribute.TypeCompound;
  import openjdk.tools.javac.code.Kinds.Kind;
  import openjdk.tools.javac.util.Assert;
  import openjdk.tools.javac.util.List;
  import openjdk.tools.javac.util.ListBuffer;
  import openjdk.tools.javac.util.Pair;
  
  /**
   * Container for all annotations (attributes in javac) on a Symbol.
   *
   * This class is explicitly mutable. Its contents will change when attributes
   * are annotated onto the Symbol. However this class depends on the facts that
   * List (in javac) is immutable.
   *
   * An instance of this class can be in one of three states:
   *
   * NOT_STARTED indicates that the Symbol this instance belongs to has not been
   * annotated (yet). Specifically if the declaration is not annotated this
   * instance will never move past NOT_STARTED. You can never go back to
   * NOT_STARTED.
   *
   * IN_PROGRESS annotations have been found on the declaration. Will be processed
   * later. You can reset to IN_PROGRESS. While IN_PROGRESS you can set the list
   * of attributes (and this moves out of the IN_PROGRESS state).
   *
   * "unnamed" this SymbolMetadata contains some attributes, possibly the final set.
   * While in this state you can only prepend or append to the attributes not set
   * it directly. You can also move back to the IN_PROGRESS state using reset().
   *
   * <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 SymbolMetadata {
  
      private static final List<Attribute.Compound> DECL_NOT_STARTED = List.of(null);
      private static final List<Attribute.Compound> DECL_IN_PROGRESS = List.of(null);
  
      /*
       * This field should never be null
       */
      private List<Attribute.Compound> attributes = DECL_NOT_STARTED;
  
      /*
       * Type attributes for this symbol.
       * This field should never be null.
       */
      private List<Attribute.TypeCompound> type_attributes = List.nil();
  
      /*
       * Type attributes of initializers in this class.
       * Unused if the current symbol is not a ClassSymbol.
       */
      private List<Attribute.TypeCompound> init_type_attributes = List.nil();
  
      /*
       * Type attributes of class initializers in this class.
       * Unused if the current symbol is not a ClassSymbol.
       */
      private List<Attribute.TypeCompound> clinit_type_attributes = List.nil();
  
      /*
       * The Symbol this SymbolMetadata instance belongs to
       */
      private final Symbol sym;
  
      public SymbolMetadata(Symbol sym) {
          this.sym = sym;
      }
  
      public List<Attribute.Compound> getDeclarationAttributes() {
          return filterDeclSentinels(attributes);
      }
  
      public List<Attribute.TypeCompound> getTypeAttributes() {
          return type_attributes;
      }
  
      public List<Attribute.TypeCompound> getInitTypeAttributes() {
          return init_type_attributes;
      }
  
      public List<Attribute.TypeCompound> getClassInitTypeAttributes() {
          return clinit_type_attributes;
      }
  
      public void setDeclarationAttributes(List<Attribute.Compound> a) {
          Assert.check(pendingCompletion() || !isStarted());
          if (a == null) {
              throw new NullPointerException();
          }
          attributes = a;
      }
  
      public void setTypeAttributes(List<Attribute.TypeCompound> a) {
          if (a == null) {
              throw new NullPointerException();
          }
          type_attributes = a;
      }
  
      public void setInitTypeAttributes(List<Attribute.TypeCompound> a) {
          if (a == null) {
              throw new NullPointerException();
          }
          init_type_attributes = a;
      }
  
      public void setClassInitTypeAttributes(List<Attribute.TypeCompound> a) {
          if (a == null) {
              throw new NullPointerException();
          }
          clinit_type_attributes = a;
      }
  
      public void setAttributes(SymbolMetadata other) {
          if (other == null) {
              throw new NullPointerException();
          }
          setDeclarationAttributes(other.getDeclarationAttributes());
          if ((sym.flags() & Flags.BRIDGE) != 0) {
              Assert.check(other.sym.kind == Kind.MTH);
              ListBuffer<TypeCompound> typeAttributes = new ListBuffer<>();
              for (TypeCompound tc : other.getTypeAttributes()) {
                  // Carry over only contractual type annotations: i.e nothing interior to method body.
                  if (!tc.position.type.isLocal())
                      typeAttributes.append(tc);
              }
              setTypeAttributes(typeAttributes.toList());
          } else {
              setTypeAttributes(other.getTypeAttributes());
          }
          if (sym.kind == Kind.TYP) {
              setInitTypeAttributes(other.getInitTypeAttributes());
              setClassInitTypeAttributes(other.getClassInitTypeAttributes());
          }
      }
  
      public SymbolMetadata reset() {
          attributes = DECL_IN_PROGRESS;
          return this;
      }
  
      public boolean isEmpty() {
          return !isStarted()
                  || pendingCompletion()
                  || attributes.isEmpty();
      }
  
      public boolean isTypesEmpty() {
          return type_attributes.isEmpty();
      }
  
      public boolean pendingCompletion() {
          return attributes == DECL_IN_PROGRESS;
      }
  
      public SymbolMetadata append(List<Attribute.Compound> l) {
          attributes = filterDeclSentinels(attributes);
  
          if (l.isEmpty()) {
              // no-op
          } else if (attributes.isEmpty()) {
              attributes = l;
          } else {
              attributes = attributes.appendList(l);
          }
          return this;
      }
  
      public SymbolMetadata appendUniqueTypes(List<Attribute.TypeCompound> l) {
          if (l.isEmpty()) {
              // no-op
          } else if (type_attributes.isEmpty()) {
              type_attributes = l;
          } else {
              // TODO: in case we expect a large number of annotations, this
              // might be inefficient.
              for (Attribute.TypeCompound tc : l) {
                  if (!type_attributes.contains(tc))
                      type_attributes = type_attributes.append(tc);
              }
          }
          return this;
      }
  
      public SymbolMetadata appendInitTypeAttributes(List<Attribute.TypeCompound> l) {
          if (l.isEmpty()) {
              // no-op
          } else if (init_type_attributes.isEmpty()) {
              init_type_attributes = l;
          } else {
              init_type_attributes = init_type_attributes.appendList(l);
          }
          return this;
      }
  
      public SymbolMetadata appendClassInitTypeAttributes(List<Attribute.TypeCompound> l) {
          if (l.isEmpty()) {
              // no-op
          } else if (clinit_type_attributes.isEmpty()) {
              clinit_type_attributes = l;
          } else {
              clinit_type_attributes = clinit_type_attributes.appendList(l);
          }
          return this;
      }
  
      public SymbolMetadata prepend(List<Attribute.Compound> l) {
          attributes = filterDeclSentinels(attributes);
  
          if (l.isEmpty()) {
              // no-op
          } else if (attributes.isEmpty()) {
              attributes = l;
          } else {
              attributes = attributes.prependList(l);
          }
          return this;
      }
  
      private List<Attribute.Compound> filterDeclSentinels(List<Attribute.Compound> a) {
          return (a == DECL_IN_PROGRESS || a == DECL_NOT_STARTED)
                  ? List.nil()
                  : a;
      }
  
      private boolean isStarted() {
          return attributes != DECL_NOT_STARTED;
      }
  
      private List<Attribute.Compound> removeFromCompoundList(List<Attribute.Compound> l, Attribute.Compound compound) {
          ListBuffer<Attribute.Compound> lb = new ListBuffer<>();
          for (Attribute.Compound c : l) {
              if (c != compound) {
                  lb.add(c);
              }
          }
          return lb.toList();
      }
  
      public void removeDeclarationMetadata(Attribute.Compound compound) {
          if (attributes.contains(compound)) {
              attributes = removeFromCompoundList(attributes, compound);
          } else {
              // slow path, it could be that attributes list contains annotation containers, so we have to dig deeper
              for (Attribute.Compound attrCompound : attributes) {
                  if (attrCompound.isSynthesized() && !attrCompound.values.isEmpty()) {
                      Pair<Symbol.MethodSymbol, Attribute> val = attrCompound.values.get(0);
                     if (val.fst.getSimpleName().contentEquals("value") &&
                              val.snd instanceof Attribute.Array) {
                          Attribute.Array arr = (Attribute.Array) val.snd;
                          if (arr.values.length != 0
                                  && arr.values[0] instanceof Attribute.Compound
                                  && arr.values[0].type == compound.type) {
                              attributes = removeFromCompoundList(attributes, attrCompound);
                          }
                      }
                  }
              }
          }
      }
  }
  