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 * Copyright (c) 2006, 2014, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
 *
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package com.sun.tools.javac.api;


import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.TypeElement;

import com.sun.tools.javac.code.Kinds.Kind;
import com.sun.tools.javac.code.Scope.CompoundScope;
import com.sun.tools.javac.code.Symbol;
import com.sun.tools.javac.comp.AttrContext;
import com.sun.tools.javac.comp.Env;
import com.sun.tools.javac.util.DefinedBy;
import com.sun.tools.javac.util.DefinedBy.Api;
import com.sun.tools.javac.util.Assert;
import com.sun.tools.javac.util.Filter;

Provides an implementation of Scope.
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.
Author:
Jonathan Gibbons;/**
 * Provides an implementation of Scope.
 *
 * <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>
 *
 * @author Jonathan Gibbons;
 */
public class JavacScope implements com.sun.source.tree.Scope {

    private static final Filter<Symbol> VALIDATOR = sym -> {
        sym.apiComplete();
        return sym.kind != Kind.ERR;
    };

    static JavacScope create(Env<AttrContext> env) {
        if (env.outer == null || env.outer == env) {
            //the "top-level" scope needs to return both imported and defined elements
            //see test CheckLocalElements
            return new JavacScope(env) {
                @Override @DefinedBy(Api.COMPILER_TREE)
                public Iterable<? extends Element> getLocalElements() {
                    CompoundScope result = new CompoundScope(env.toplevel.packge);
                    result.prependSubScope(env.toplevel.toplevelScope);
                    result.prependSubScope(env.toplevel.namedImportScope);
                    return result.getSymbols(VALIDATOR);
                }
            };
        } else {
            return new JavacScope(env);
        }
    }

    protected final Env<AttrContext> env;

    private JavacScope(Env<AttrContext> env) {
        this.env = Assert.checkNonNull(env);
    }

    @DefinedBy(Api.COMPILER_TREE)
    public JavacScope getEnclosingScope() {
        if (env.outer != null && env.outer != env) {
            return create(env.outer);
        } else {
            // synthesize an outermost "star-import" scope
            return new JavacScope(env) {
                public boolean isStarImportScope() {
                    return true;
                }
                @DefinedBy(Api.COMPILER_TREE)
                public JavacScope getEnclosingScope() {
                    return null;
                }
                @DefinedBy(Api.COMPILER_TREE)
                public Iterable<? extends Element> getLocalElements() {
                    return env.toplevel.starImportScope.getSymbols(VALIDATOR);
                }
            };
        }
    }

    @DefinedBy(Api.COMPILER_TREE)
    public TypeElement getEnclosingClass() {
        // hide the dummy class that javac uses to enclose the top level declarations
        return (env.outer == null || env.outer == env ? null : env.enclClass.sym);
    }

    @DefinedBy(Api.COMPILER_TREE)
    public ExecutableElement getEnclosingMethod() {
        return (env.enclMethod == null ? null : env.enclMethod.sym);
    }

    @DefinedBy(Api.COMPILER_TREE)
    public Iterable<? extends Element> getLocalElements() {
        return env.info.getLocalElements();
    }

    public Env<AttrContext> getEnv() {
        return env;
    }

    public boolean isStarImportScope() {
        return false;
    }

    public boolean equals(Object other) {
        if (other instanceof JavacScope) {
            JavacScope s = (JavacScope) other;
            return (env.equals(s.env)
                && isStarImportScope() == s.isStarImportScope());
        } else
            return false;
    }

    public int hashCode() {
        return env.hashCode() + (isStarImportScope() ? 1 : 0);
    }

    public String toString() {
        return "JavacScope[env=" + env + ",starImport=" + isStarImportScope() + "]";
    }
}