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	/*
	* 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.
	*/

	/*
	* This file is available under and governed by the GNU General Public
	* License version 2 only, as published by the Free Software Foundation.
	* However, the following notice accompanied the original version of this
	* file:
	*
	* ASM: a very small and fast Java bytecode manipulation framework
	* Copyright (c) 2000-2011 INRIA, France Telecom
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	* 3. Neither the name of the copyright holders nor the names of its
	* contributors may be used to endorse or promote products derived from
	* this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE.
	*/
	package jdk.internal.org.objectweb.asm.util;

	import jdk.internal.org.objectweb.asm.Opcodes;
	import jdk.internal.org.objectweb.asm.signature.SignatureVisitor;

	/**
	* A {@link SignatureVisitor} that checks that its methods are properly used.
	*
	* @author Eric Bruneton
	*/
	public class CheckSignatureAdapter extends SignatureVisitor {

	/**
	* Type to be used to check class signatures. See
	* {@link #CheckSignatureAdapter(int, SignatureVisitor)
	* CheckSignatureAdapter}.
	*/
	public static final int CLASS_SIGNATURE = 0;

	/**
	* Type to be used to check method signatures. See
	* {@link #CheckSignatureAdapter(int, SignatureVisitor)
	* CheckSignatureAdapter}.
	*/
	public static final int METHOD_SIGNATURE = 1;

	/**
	* Type to be used to check type signatures.See
	* {@link #CheckSignatureAdapter(int, SignatureVisitor)
	* CheckSignatureAdapter}.
	*/
	public static final int TYPE_SIGNATURE = 2;

	private static final int EMPTY = 1;

	private static final int FORMAL = 2;

	private static final int BOUND = 4;

	private static final int SUPER = 8;

	private static final int PARAM = 16;

	private static final int RETURN = 32;

	private static final int SIMPLE_TYPE = 64;

	private static final int CLASS_TYPE = 128;

	private static final int END = 256;

	/**
	* Type of the signature to be checked.
	*/
	private final int type;

	/**
	* State of the automaton used to check the order of method calls.
	*/
	private int state;

	/**
	* <tt>true</tt> if the checked type signature can be 'V'.
	*/
	private boolean canBeVoid;

	/**
	* The visitor to which this adapter must delegate calls. May be
	* <tt>null</tt>.
	*/
	private final SignatureVisitor sv;

	/**
	* Creates a new {@link CheckSignatureAdapter} object. <i>Subclasses must
	* not use this constructor</i>. Instead, they must use the
	* {@link #CheckSignatureAdapter(int, int, SignatureVisitor)} version.
	*
	* @param type
	* the type of signature to be checked. See
	* {@link #CLASS_SIGNATURE}, {@link #METHOD_SIGNATURE} and
	* {@link #TYPE_SIGNATURE}.
	* @param sv
	* the visitor to which this adapter must delegate calls. May be
	* <tt>null</tt>.
	*/
	public CheckSignatureAdapter(final int type, final SignatureVisitor sv) {
	this(Opcodes.ASM5, type, sv);
	}

	/**
	* Creates a new {@link CheckSignatureAdapter} object.
	*
	* @param api
	* the ASM API version implemented by this visitor. Must be one
	* of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.
	* @param type
	* the type of signature to be checked. See
	* {@link #CLASS_SIGNATURE}, {@link #METHOD_SIGNATURE} and
	* {@link #TYPE_SIGNATURE}.
	* @param sv
	* the visitor to which this adapter must delegate calls. May be
	* <tt>null</tt>.
	*/
	protected CheckSignatureAdapter(final int api, final int type,
	final SignatureVisitor sv) {
	super(api);
	this.type = type;
	this.state = EMPTY;
	this.sv = sv;
	}

	// class and method signatures

	@Override
	public void visitFormalTypeParameter(final String name) {
	if (type == TYPE_SIGNATURE
	\|\| (state != EMPTY && state != FORMAL && state != BOUND)) {
	throw new IllegalStateException();
	}
	CheckMethodAdapter.checkIdentifier(name, "formal type parameter");
	state = FORMAL;
	if (sv != null) {
	sv.visitFormalTypeParameter(name);
	}
	}

	@Override
	public SignatureVisitor visitClassBound() {
	if (state != FORMAL) {
	throw new IllegalStateException();
	}
	state = BOUND;
	SignatureVisitor v = sv == null ? null : sv.visitClassBound();
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	@Override
	public SignatureVisitor visitInterfaceBound() {
	if (state != FORMAL && state != BOUND) {
	throw new IllegalArgumentException();
	}
	SignatureVisitor v = sv == null ? null : sv.visitInterfaceBound();
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	// class signatures

	@Override
	public SignatureVisitor visitSuperclass() {
	if (type != CLASS_SIGNATURE \|\| (state & (EMPTY \| FORMAL \| BOUND)) == 0) {
	throw new IllegalArgumentException();
	}
	state = SUPER;
	SignatureVisitor v = sv == null ? null : sv.visitSuperclass();
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	@Override
	public SignatureVisitor visitInterface() {
	if (state != SUPER) {
	throw new IllegalStateException();
	}
	SignatureVisitor v = sv == null ? null : sv.visitInterface();
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	// method signatures

	@Override
	public SignatureVisitor visitParameterType() {
	if (type != METHOD_SIGNATURE
	\|\| (state & (EMPTY \| FORMAL \| BOUND \| PARAM)) == 0) {
	throw new IllegalArgumentException();
	}
	state = PARAM;
	SignatureVisitor v = sv == null ? null : sv.visitParameterType();
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	@Override
	public SignatureVisitor visitReturnType() {
	if (type != METHOD_SIGNATURE
	\|\| (state & (EMPTY \| FORMAL \| BOUND \| PARAM)) == 0) {
	throw new IllegalArgumentException();
	}
	state = RETURN;
	SignatureVisitor v = sv == null ? null : sv.visitReturnType();
	CheckSignatureAdapter cv = new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	cv.canBeVoid = true;
	return cv;
	}

	@Override
	public SignatureVisitor visitExceptionType() {
	if (state != RETURN) {
	throw new IllegalStateException();
	}
	SignatureVisitor v = sv == null ? null : sv.visitExceptionType();
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	// type signatures

	@Override
	public void visitBaseType(final char descriptor) {
	if (type != TYPE_SIGNATURE \|\| state != EMPTY) {
	throw new IllegalStateException();
	}
	if (descriptor == 'V') {
	if (!canBeVoid) {
	throw new IllegalArgumentException();
	}
	} else {
	if ("ZCBSIFJD".indexOf(descriptor) == -1) {
	throw new IllegalArgumentException();
	}
	}
	state = SIMPLE_TYPE;
	if (sv != null) {
	sv.visitBaseType(descriptor);
	}
	}

	@Override
	public void visitTypeVariable(final String name) {
	if (type != TYPE_SIGNATURE \|\| state != EMPTY) {
	throw new IllegalStateException();
	}
	CheckMethodAdapter.checkIdentifier(name, "type variable");
	state = SIMPLE_TYPE;
	if (sv != null) {
	sv.visitTypeVariable(name);
	}
	}

	@Override
	public SignatureVisitor visitArrayType() {
	if (type != TYPE_SIGNATURE \|\| state != EMPTY) {
	throw new IllegalStateException();
	}
	state = SIMPLE_TYPE;
	SignatureVisitor v = sv == null ? null : sv.visitArrayType();
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	@Override
	public void visitClassType(final String name) {
	if (type != TYPE_SIGNATURE \|\| state != EMPTY) {
	throw new IllegalStateException();
	}
	CheckMethodAdapter.checkInternalName(name, "class name");
	state = CLASS_TYPE;
	if (sv != null) {
	sv.visitClassType(name);
	}
	}

	@Override
	public void visitInnerClassType(final String name) {
	if (state != CLASS_TYPE) {
	throw new IllegalStateException();
	}
	CheckMethodAdapter.checkIdentifier(name, "inner class name");
	if (sv != null) {
	sv.visitInnerClassType(name);
	}
	}

	@Override
	public void visitTypeArgument() {
	if (state != CLASS_TYPE) {
	throw new IllegalStateException();
	}
	if (sv != null) {
	sv.visitTypeArgument();
	}
	}

	@Override
	public SignatureVisitor visitTypeArgument(final char wildcard) {
	if (state != CLASS_TYPE) {
	throw new IllegalStateException();
	}
	if ("+-=".indexOf(wildcard) == -1) {
	throw new IllegalArgumentException();
	}
	SignatureVisitor v = sv == null ? null : sv.visitTypeArgument(wildcard);
	return new CheckSignatureAdapter(TYPE_SIGNATURE, v);
	}

	@Override
	public void visitEnd() {
	if (state != CLASS_TYPE) {
	throw new IllegalStateException();
	}
	state = END;
	if (sv != null) {
	sv.visitEnd();
	}
	}
	}

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