content: /*
   * Copyright (c) 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 java.lang.reflect;
  
  import dalvik.annotation.optimization.FastNative;
  import java.lang.annotation.*;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Objects;
  import libcore.reflect.AnnotatedElements;
  
  /**
   * Information about method parameters.
   *
   * A {@code Parameter} provides information about method parameters,
   * including its name and modifiers.  It also provides an alternate
   * means of obtaining attributes for the parameter.
   *
   * @since 1.8
   */
  public final class Parameter implements AnnotatedElement {
      // Android-changed: Extensive modifications made throughout the class for ART.
      // Android-removed: Type annotations runtime code. Not supported on Android.
      // Android-removed: Annotation retrieval is implemented natively in ART.
  
      private final String name;
      private final int modifiers;
      private final Executable executable;
      private final int index;
  
      /**
       * Package-private constructor for {@code Parameter}.
       *
       * If method parameter data is present in the classfile, then the
       * JVM creates {@code Parameter} objects directly.  If it is
       * absent, however, then {@code Executable} uses this constructor
       * to synthesize them.
       *
       * @param name The name of the parameter.
       * @param modifiers The modifier flags for the parameter.
       * @param executable The executable which defines this parameter.
       * @param index The index of the parameter.
       */
      Parameter(String name,
                int modifiers,
                Executable executable,
                int index) {
          this.name = name;
          this.modifiers = modifiers;
          this.executable = executable;
          this.index = index;
      }
  
      /**
       * Compares based on the executable and the index.
       *
       * @param obj The object to compare.
       * @return Whether or not this is equal to the argument.
       */
      public boolean equals(Object obj) {
          if(obj instanceof Parameter) {
              Parameter other = (Parameter)obj;
              return (other.executable.equals(executable) &&
                      other.index == index);
          }
          return false;
      }
  
      /**
       * Returns a hash code based on the executable's hash code and the
       * index.
       *
       * @return A hash code based on the executable's hash code.
       */
      public int hashCode() {
          return executable.hashCode() ^ index;
      }
  
      // Android-changed: Removed references in javadoc to the class file format.
      /**
       * Returns true if the parameter has a name; returns false otherwise.
       * Whether a parameter has a name is determined by compiler options
       * and whether the parameter is synthesized.
       *
       * @return true if and only if the parameter has a name
       */
      public boolean isNamePresent() {
          return executable.hasRealParameterData() && name != null;
      }
  
      /**
       * Returns a string describing this parameter.  The format is the
       * modifiers for the parameter, if any, in canonical order as
       * recommended by <cite>The Java&trade; Language
       * Specification</cite>, followed by the fully- qualified type of
       * the parameter (excluding the last [] if the parameter is
       * variable arity), followed by "..." if the parameter is variable
       * arity, followed by a space, followed by the name of the
       * parameter.
       *
       * @return A string representation of the parameter and associated
       * information.
       */
      public String toString() {
          final StringBuilder sb = new StringBuilder();
          final Type type = getParameterizedType();
          final String typename = type.getTypeName();
  
          sb.append(Modifier.toString(getModifiers()));
  
          if(0 != modifiers)
              sb.append(' ');
  
          if(isVarArgs())
              sb.append(typename.replaceFirst("\\[\\]$", "..."));
          else
              sb.append(typename);
  
          sb.append(' ');
          sb.append(getName());
  
          return sb.toString();
      }
  
      /**
       * Return the {@code Executable} which declares this parameter.
       *
       * @return The {@code Executable} declaring this parameter.
       */
      public Executable getDeclaringExecutable() {
          return executable;
      }
  
      /**
       * Get the modifier flags for this the parameter represented by
       * this {@code Parameter} object.
       *
       * @return The modifier flags for this parameter.
       */
      public int getModifiers() {
          return modifiers;
      }
  
      /**
       * Returns the name of the parameter.  If the parameter's name is
       * {@linkplain #isNamePresent() present}, then this method returns
       * the name provided by the class file. Otherwise, this method
       * synthesizes a name of the form argN, where N is the index of
       * the parameter in the descriptor of the method which declares
       * the parameter.
       *
       * @return The name of the parameter, either provided by the class
       *         file or synthesized if the class file does not provide
       *         a name.
       */
      public String getName() {
          // Note: empty strings as paramete names are now outlawed.
          // The .equals("") is for compatibility with current JVM
          // behavior.  It may be removed at some point.
          if(name == null || name.equals(""))
              return "arg" + index;
          else
              return name;
      }
  
      // Package-private accessor to the real name field.
      String getRealName() {
          return name;
      }
  
      /**
       * Returns a {@code Type} object that identifies the parameterized
       * type for the parameter represented by this {@code Parameter}
       * object.
       *
       * @return a {@code Type} object identifying the parameterized
       * type of the parameter represented by this object
       */
      public Type getParameterizedType() {
          Type tmp = parameterTypeCache;
          if (null == tmp) {
              tmp = executable.getAllGenericParameterTypes()[index];
              parameterTypeCache = tmp;
          }
  
          return tmp;
      }
  
      private transient volatile Type parameterTypeCache = null;
  
      /**
       * Returns a {@code Class} object that identifies the
       * declared type for the parameter represented by this
       * {@code Parameter} object.
       *
       * @return a {@code Class} object identifying the declared
       * type of the parameter represented by this object
       */
      public Class<?> getType() {
          Class<?> tmp = parameterClassCache;
          if (null == tmp) {
              tmp = executable.getParameterTypes()[index];
              parameterClassCache = tmp;
          }
          return tmp;
      }
  
      private transient volatile Class<?> parameterClassCache = null;
  
      /**
       * Returns {@code true} if this parameter is implicitly declared
       * in source code; returns {@code false} otherwise.
       *
       * @return true if and only if this parameter is implicitly
       * declared as defined by <cite>The Java&trade; Language
       * Specification</cite>.
       */
      public boolean isImplicit() {
          return Modifier.isMandated(getModifiers());
      }
  
      /**
       * Returns {@code true} if this parameter is neither implicitly
       * nor explicitly declared in source code; returns {@code false}
       * otherwise.
       *
       * @jls 13.1 The Form of a Binary
       * @return true if and only if this parameter is a synthetic
       * construct as defined by
       * <cite>The Java&trade; Language Specification</cite>.
       */
      public boolean isSynthetic() {
          return Modifier.isSynthetic(getModifiers());
      }
  
      /**
       * Returns {@code true} if this parameter represents a variable
       * argument list; returns {@code false} otherwise.
       *
       * @return {@code true} if an only if this parameter represents a
       * variable argument list.
       */
      public boolean isVarArgs() {
          return executable.isVarArgs() &&
              index == executable.getParameterCount() - 1;
      }
  
  
      /**
       * {@inheritDoc}
       * @throws NullPointerException {@inheritDoc}
       */
      public <T extends Annotation> T getAnnotation(Class<T> annotationClass) {
          Objects.requireNonNull(annotationClass);
          // Android-changed: getAnnotation(Class) Uses native code to obtain annotation information.
          return getAnnotationNative(executable, index, annotationClass);
      }
      // Android-added: getAnnotation(Class) Uses native code to obtain annotation information.
      @FastNative
      private static native <A extends Annotation> A getAnnotationNative(
              Executable executable, int parameterIndex, Class<A> annotationType);
  
      /**
       * {@inheritDoc}
       * @throws NullPointerException {@inheritDoc}
       */
      @Override
      public <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass) {
          // Android-changed: getAnnotationsByType(Class), Android uses AnnotatedElements instead.
          return AnnotatedElements.getDirectOrIndirectAnnotationsByType(this, annotationClass);
      }
  
      /**
       * {@inheritDoc}
       */
      public Annotation[] getDeclaredAnnotations() {
          return executable.getParameterAnnotations()[index];
      }
  
      /**
       * @throws NullPointerException {@inheritDoc}
       */
      public <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass) {
          // Only annotations on classes are inherited, for all other
          // objects getDeclaredAnnotation is the same as
          // getAnnotation.
          return getAnnotation(annotationClass);
      }
  
      /**
       * @throws NullPointerException {@inheritDoc}
       */
      @Override
      public <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass) {
          // Only annotations on classes are inherited, for all other
          // objects getDeclaredAnnotations is the same as
          // getAnnotations.
          return getAnnotationsByType(annotationClass);
      }
  
      /**
       * {@inheritDoc}
       */
      public Annotation[] getAnnotations() {
          return getDeclaredAnnotations();
      }
  
  }
  