/*

 * Copyright (c) 2005, 2014, 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

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package com.sun.source.util;

import java.lang.reflect.Method;

import javax.annotation.processing.ProcessingEnvironment;

import javax.lang.model.element.AnnotationMirror;

import javax.lang.model.element.AnnotationValue;

import javax.lang.model.element.Element;

import javax.lang.model.element.ExecutableElement;

import javax.lang.model.element.TypeElement;

import javax.lang.model.type.DeclaredType;

import javax.lang.model.type.ErrorType;

import javax.lang.model.type.TypeMirror;

import javax.tools.Diagnostic;

import javax.tools.JavaCompiler.CompilationTask;

import com.sun.source.tree.CatchTree;

import com.sun.source.tree.ClassTree;

import com.sun.source.tree.CompilationUnitTree;

import com.sun.source.tree.MethodTree;

import com.sun.source.tree.Scope;

import com.sun.source.tree.Tree;

/**

 * Bridges JSR 199, JSR 269, and the Tree API.

 *

 * @author Peter von der Ahé

 */

public abstract class Trees {

    /**

     * Returns a Trees object for a given CompilationTask.

     * @param task the compilation task for which to get the Trees object

     * @throws IllegalArgumentException if the task does not support the Trees API.

     * @return the Trees object

     */

    public static Trees instance(CompilationTask task) {

        String taskClassName = task.getClass().getName();

        if (!taskClassName.equals("com.sun.tools.javac.api.JavacTaskImpl")

                && !taskClassName.equals("com.sun.tools.javac.api.BasicJavacTask"))

            throw new IllegalArgumentException();

        return getJavacTrees(CompilationTask.class, task);

    }

    /**

     * Returns a Trees object for a given ProcessingEnvironment.

     * @param env the processing environment for which to get the Trees object

     * @throws IllegalArgumentException if the env does not support the Trees API.

     * @return the Trees object

     */

    public static Trees instance(ProcessingEnvironment env) {

        if (!env.getClass().getName().equals("com.sun.tools.javac.processing.JavacProcessingEnvironment"))

            throw new IllegalArgumentException();

        return getJavacTrees(ProcessingEnvironment.class, env);

    }

    static Trees getJavacTrees(Class<?> argType, Object arg) {

        try {

            ClassLoader cl = arg.getClass().getClassLoader();

            Class<?> c = Class.forName("com.sun.tools.javac.api.JavacTrees", false, cl);

            argType = Class.forName(argType.getName(), false, cl);

            Method m = c.getMethod("instance", argType);

            return (Trees) m.invoke(null, arg);

        } catch (ReflectiveOperationException e) {

            throw new AssertionError(e);

        }

    }

    /**

     * Returns a utility object for obtaining source positions.

     * @return the utility object for obtaining source positions

     */

    public abstract SourcePositions getSourcePositions();

    /**

     * Returns the Tree node for a given Element.

     * Returns {@code null} if the node can not be found.

     * @param element the element

     * @return the tree node

     */

    public abstract Tree getTree(Element element);

    /**

     * Returns the ClassTree node for a given TypeElement.

     * Returns {@code null} if the node can not be found.

     * @param element the element

     * @return the class tree node

     */

    public abstract ClassTree getTree(TypeElement element);

    /**

     * Returns the MethodTree node for a given ExecutableElement.

     * Returns {@code null} if the node can not be found.

     * @param method the executable element

     * @return the method tree node

     */

    public abstract MethodTree getTree(ExecutableElement method);

    /**

     * Returns the Tree node for an AnnotationMirror on a given Element.

     * Returns {@code null} if the node can not be found.

     * @param e the element

     * @param a the annotation mirror

     * @return the tree node

     */

    public abstract Tree getTree(Element e, AnnotationMirror a);

    /**

     * Returns the Tree node for an AnnotationValue for an AnnotationMirror on a given Element.

     * Returns {@code null} if the node can not be found.

     * @param e the element

     * @param a the annotation mirror

     * @param v the annotation value

     * @return the tree node

     */

    public abstract Tree getTree(Element e, AnnotationMirror a, AnnotationValue v);

    /**

     * Returns the path to tree node within the specified compilation unit.

     * @param unit the compilation unit

     * @param node the tree node

     * @return the tree path

     */

    public abstract TreePath getPath(CompilationUnitTree unit, Tree node);

    /**

     * Returns the TreePath node for a given Element.

     * Returns {@code null} if the node can not be found.

     * @param e the element

     * @return the tree path

     */

    public abstract TreePath getPath(Element e);

    /**

     * Returns the TreePath node for an AnnotationMirror on a given Element.

     * Returns {@code null} if the node can not be found.

     * @param e the element

     * @param a the annotation mirror

     * @return the tree path

     */

    public abstract TreePath getPath(Element e, AnnotationMirror a);

    /**

     * Returns the TreePath node for an AnnotationValue for an AnnotationMirror on a given Element.

     * Returns {@code null} if the node can not be found.

     * @param e the element

     * @param a the annotation mirror

     * @param v the annotation value

     * @return the tree path

     */

    public abstract TreePath getPath(Element e, AnnotationMirror a, AnnotationValue v);

    /**

     * Returns the Element for the Tree node identified by a given TreePath.

     * Returns {@code null} if the element is not available.

     * @param path the tree path

     * @return the element

     * @throws IllegalArgumentException is the TreePath does not identify

     * a Tree node that might have an associated Element.

     */

    public abstract Element getElement(TreePath path);

    /**

     * Returns the TypeMirror for the Tree node identified by a given TreePath.

     * Returns {@code null} if the TypeMirror is not available.

     * @param path the tree path

     * @return the type mirror

     * @throws IllegalArgumentException is the TreePath does not identify

     * a Tree node that might have an associated TypeMirror.

     */

    public abstract TypeMirror getTypeMirror(TreePath path);

    /**

     * Returns the Scope for the Tree node identified by a given TreePath.

     * Returns {@code null} if the Scope is not available.

     * @param path the tree path

     * @return the scope

     */

    public abstract Scope getScope(TreePath path);

    /**

     * Returns the doc comment, if any, for the Tree node identified by a given TreePath.

     * Returns {@code null} if no doc comment was found.

     * @see DocTrees#getDocCommentTree(TreePath)

     * @param path the tree path

     * @return the doc comment

     */

    public abstract String getDocComment(TreePath path);

    /**

     * Checks whether a given type is accessible in a given scope.

     * @param scope the scope to be checked

     * @param type the type to be checked

     * @return true if {@code type} is accessible

     */

    public abstract boolean isAccessible(Scope scope, TypeElement type);

    /**

     * Checks whether the given element is accessible as a member of the given

     * type in a given scope.

     * @param scope the scope to be checked

     * @param member the member to be checked

     * @param type the type for which to check if the member is accessible

     * @return true if {@code member} is accessible in {@code type}

     */

    public abstract boolean isAccessible(Scope scope, Element member, DeclaredType type);

    /**

      * Returns the original type from the ErrorType object.

      * @param errorType The errorType for which we want to get the original type.

      * @return javax.lang.model.type.TypeMirror corresponding to the original type, replaced by the ErrorType.

      */

    public abstract TypeMirror getOriginalType(ErrorType errorType);

    /**

     * Prints a message of the specified kind at the location of the

     * tree within the provided compilation unit

     *

     * @param kind the kind of message

     * @param msg  the message, or an empty string if none

     * @param t    the tree to use as a position hint

     * @param root the compilation unit that contains tree

     */

    public abstract void printMessage(Diagnostic.Kind kind, CharSequence msg,

            com.sun.source.tree.Tree t,

            com.sun.source.tree.CompilationUnitTree root);

    /**

     * Returns the lub of an exception parameter declared in a catch clause.

     * @param tree the tree for the catch clause

     * @return The lub of the exception parameter

     */

    public abstract TypeMirror getLub(CatchTree tree);

}