content: /*
   * Copyright (c) 2005, 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.model;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.EnumSet;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.stream.Collectors;
  
  import jdkx.lang.model.element.*;
  import jdkx.lang.model.type.*;
  
  import openjdk.tools.javac.code.*;
  import openjdk.tools.javac.code.Symbol.*;
  import openjdk.tools.javac.jvm.ClassReader;
  import openjdk.tools.javac.util.*;
  import openjdk.tools.javac.util.DefinedBy.Api;
  
  import static openjdk.tools.javac.code.Kinds.Kind.*;
  
  /**
   * Utility methods for operating on types.
   *
   * <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></p>
   */
  public class JavacTypes implements jdkx.lang.model.util.Types {
  
      private final Symtab syms;
      private final Types types;
  
      public static JavacTypes instance(Context context) {
          JavacTypes instance = context.get(JavacTypes.class);
          if (instance == null)
              instance = new JavacTypes(context);
          return instance;
      }
  
      protected JavacTypes(Context context) {
          context.put(JavacTypes.class, this);
          //Need ensure ClassReader is initialized before Symtab:
          ClassReader.instance(context);
          syms = Symtab.instance(context);
          types = Types.instance(context);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public Element asElement(TypeMirror t) {
          switch (t.getKind()) {
              case DECLARED:
              case INTERSECTION:
              case ERROR:
              case TYPEVAR:
                  Type type = cast(Type.class, t);
                  return type.asElement();
              default:
                  return null;
          }
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public boolean isSameType(TypeMirror t1, TypeMirror t2) {
          if (t1.getKind() == TypeKind.WILDCARD || t2.getKind() == TypeKind.WILDCARD) {
              return false;
          }
          return types.isSameType((Type) t1, (Type) t2);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public boolean isSubtype(TypeMirror t1, TypeMirror t2) {
          validateTypeNotIn(t1, EXEC_OR_PKG_OR_MOD);
          validateTypeNotIn(t2, EXEC_OR_PKG_OR_MOD);
          return types.isSubtype((Type) t1, (Type) t2);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public boolean isAssignable(TypeMirror t1, TypeMirror t2) {
          validateTypeNotIn(t1, EXEC_OR_PKG_OR_MOD);
          validateTypeNotIn(t2, EXEC_OR_PKG_OR_MOD);
          return types.isAssignable((Type) t1, (Type) t2);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public boolean contains(TypeMirror t1, TypeMirror t2) {
          validateTypeNotIn(t1, EXEC_OR_PKG_OR_MOD);
          validateTypeNotIn(t2, EXEC_OR_PKG_OR_MOD);
          return types.containsType((Type) t1, (Type) t2);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public boolean isSubsignature(ExecutableType m1, ExecutableType m2) {
          return types.isSubSignature((Type) m1, (Type) m2);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public List<Type> directSupertypes(TypeMirror t) {
          validateTypeNotIn(t, EXEC_OR_PKG_OR_MOD);
          Type ty = (Type)t;
          return types.directSupertypes(ty).stream()
                  .map(Type::stripMetadataIfNeeded)
                  .collect(Collectors.toList());
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public TypeMirror erasure(TypeMirror t) {
          TypeKind kind = t.getKind();
          if (kind == TypeKind.PACKAGE || kind == TypeKind.MODULE)
              throw new IllegalArgumentException(t.toString());
          return types.erasure((Type)t).stripMetadataIfNeeded();
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public TypeElement boxedClass(PrimitiveType p) {
          return types.boxedClass((Type) p);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public PrimitiveType unboxedType(TypeMirror t) {
          if (t.getKind() != TypeKind.DECLARED)
              throw new IllegalArgumentException(t.toString());
          Type unboxed = types.unboxedType((Type) t);
          if (! unboxed.isPrimitive())    // only true primitives, not void
              throw new IllegalArgumentException(t.toString());
          return (PrimitiveType)unboxed;
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public TypeMirror capture(TypeMirror t) {
          validateTypeNotIn(t, EXEC_OR_PKG_OR_MOD);
          return types.capture((Type)t).stripMetadataIfNeeded();
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public PrimitiveType getPrimitiveType(TypeKind kind) {
          switch (kind) {
          case BOOLEAN:   return syms.booleanType;
          case BYTE:      return syms.byteType;
          case SHORT:     return syms.shortType;
          case INT:       return syms.intType;
          case LONG:      return syms.longType;
          case CHAR:      return syms.charType;
          case FLOAT:     return syms.floatType;
          case DOUBLE:    return syms.doubleType;
          default:
              throw new IllegalArgumentException("Not a primitive type: " + kind);
          }
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public NullType getNullType() {
          return (NullType) syms.botType;
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public NoType getNoType(TypeKind kind) {
          switch (kind) {
          case VOID:      return syms.voidType;
          case NONE:      return Type.noType;
          default:
              throw new IllegalArgumentException(kind.toString());
          }
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public ArrayType getArrayType(TypeMirror componentType) {
          switch (componentType.getKind()) {
          case VOID:
          case EXECUTABLE:
          case WILDCARD:  // heh!
          case PACKAGE:
          case MODULE:
              throw new IllegalArgumentException(componentType.toString());
          }
          return new Type.ArrayType((Type) componentType, syms.arrayClass);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public WildcardType getWildcardType(TypeMirror extendsBound,
                                          TypeMirror superBound) {
          BoundKind bkind;
          Type bound;
          if (extendsBound == null && superBound == null) {
              bkind = BoundKind.UNBOUND;
              bound = syms.objectType;
          } else if (superBound == null) {
              bkind = BoundKind.EXTENDS;
              bound = (Type) extendsBound;
          } else if (extendsBound == null) {
              bkind = BoundKind.SUPER;
              bound = (Type) superBound;
          } else {
              throw new IllegalArgumentException(
                      "Extends and super bounds cannot both be provided");
          }
          switch (bound.getKind()) {
          case ARRAY:
          case DECLARED:
          case ERROR:
          case TYPEVAR:
          case OTHER:
              return new Type.WildcardType(bound, bkind, syms.boundClass);
          default:
              throw new IllegalArgumentException(bound.toString());
          }
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public DeclaredType getDeclaredType(TypeElement typeElem,
                                          TypeMirror... typeArgs) {
          ClassSymbol sym = (ClassSymbol) typeElem;
  
          if (typeArgs.length == 0)
              return (DeclaredType) sym.erasure(types);
          if (sym.type.getEnclosingType().isParameterized())
              throw new IllegalArgumentException(sym.toString());
  
          return getDeclaredType0(sym.type.getEnclosingType(), sym, typeArgs);
      }
  
      @DefinedBy(Api.LANGUAGE_MODEL)
      public DeclaredType getDeclaredType(DeclaredType enclosing,
                                          TypeElement typeElem,
                                          TypeMirror... typeArgs) {
          if (enclosing == null)
              return getDeclaredType(typeElem, typeArgs);
  
          ClassSymbol sym = (ClassSymbol) typeElem;
          Type outer = (Type) enclosing;
  
          if (outer.tsym != sym.owner.enclClass())
              throw new IllegalArgumentException(enclosing.toString());
          if (!outer.isParameterized())
              return getDeclaredType(typeElem, typeArgs);
  
          return getDeclaredType0(outer, sym, typeArgs);
      }
      // where
          private DeclaredType getDeclaredType0(Type outer,
                                                ClassSymbol sym,
                                                TypeMirror... typeArgs) {
              if (typeArgs.length != sym.type.getTypeArguments().length())
                  throw new IllegalArgumentException(
                  "Incorrect number of type arguments");
  
              ListBuffer<Type> targs = new ListBuffer<>();
              for (TypeMirror t : typeArgs) {
                  if (!(t instanceof ReferenceType || t instanceof WildcardType))
                      throw new IllegalArgumentException(t.toString());
                  targs.append((Type) t);
              }
              // TODO: Would like a way to check that type args match formals.
  
              return (DeclaredType) new Type.ClassType(outer, targs.toList(), sym);
          }
  
      /**
       * Returns the type of an element when that element is viewed as
       * a member of, or otherwise directly contained by, a given type.
       * For example,
       * when viewed as a member of the parameterized type {@code Set<String>},
       * the {@code Set.add} method is an {@code ExecutableType}
       * whose parameter is of type {@code String}.
       *
       * @param containing  the containing type
       * @param element     the element
       * @return the type of the element as viewed from the containing type
       * @throws IllegalArgumentException if the element is not a valid one
       *          for the given type
       */
      @DefinedBy(Api.LANGUAGE_MODEL)
      public TypeMirror asMemberOf(DeclaredType containing, Element element) {
          Type site = (Type)containing;
          Symbol sym = (Symbol)element;
          if (types.asSuper(site, sym.getEnclosingElement()) == null)
              throw new IllegalArgumentException(sym + "@" + site);
          return types.memberType(site, sym);
      }
  
  
      private static final Set<TypeKind> EXEC_OR_PKG_OR_MOD =
          EnumSet.of(TypeKind.EXECUTABLE, TypeKind.PACKAGE, TypeKind.MODULE);
  
      /**
       * Throws an IllegalArgumentException if a type's kind is one of a set.
       */
      private void validateTypeNotIn(TypeMirror t, Set<TypeKind> invalidKinds) {
          if (invalidKinds.contains(t.getKind()))
              throw new IllegalArgumentException(t.toString());
      }
  
      /**
       * Returns an object cast to the specified type.
       * @throws NullPointerException if the object is {@code null}
       * @throws IllegalArgumentException if the object is of the wrong type
       */
      private static <T> T cast(Class<T> clazz, Object o) {
          if (! clazz.isInstance(o))
              throw new IllegalArgumentException(o.toString());
          return clazz.cast(o);
      }
  
      public Set<MethodSymbol> getOverriddenMethods(Element elem) {
          if (elem.getKind() != ElementKind.METHOD
                  || elem.getModifiers().contains(Modifier.STATIC)
                  || elem.getModifiers().contains(Modifier.PRIVATE))
              return Collections.emptySet();
  
          if (!(elem instanceof MethodSymbol))
              throw new IllegalArgumentException();
  
          MethodSymbol m = (MethodSymbol) elem;
          ClassSymbol origin = (ClassSymbol) m.owner;
  
          Set<MethodSymbol> results = new LinkedHashSet<>();
          for (Type t : types.closure(origin.type)) {
              if (t != origin.type) {
                  ClassSymbol c = (ClassSymbol) t.tsym;
                  for (Symbol sym : c.members().getSymbolsByName(m.name)) {
                      if (sym.kind == MTH && m.overrides(sym, origin, types, true)) {
                          results.add((MethodSymbol) sym);
                      }
                  }
              }
          }
  
          return results;
      }
  }
  