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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 java.util.EnumSet;
	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)}.
	*/
	public static final int CLASS_SIGNATURE = 0;

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

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

	/** The valid automaton states for a {@link #visitFormalTypeParameter} method call. */
	private static final EnumSet<State> VISIT_FORMAL_TYPE_PARAMETER_STATES =
	EnumSet.of(State.EMPTY, State.FORMAL, State.BOUND);

	/** The valid automaton states for a {@link #visitClassBound} method call. */
	private static final EnumSet<State> VISIT_CLASS_BOUND_STATES = EnumSet.of(State.FORMAL);

	/** The valid automaton states for a {@link #visitInterfaceBound} method call. */
	private static final EnumSet<State> VISIT_INTERFACE_BOUND_STATES =
	EnumSet.of(State.FORMAL, State.BOUND);

	/** The valid automaton states for a {@link #visitSuperclass} method call. */
	private static final EnumSet<State> VISIT_SUPER_CLASS_STATES =
	EnumSet.of(State.EMPTY, State.FORMAL, State.BOUND);

	/** The valid automaton states for a {@link #visitInterface} method call. */
	private static final EnumSet<State> VISIT_INTERFACE_STATES = EnumSet.of(State.SUPER);

	/** The valid automaton states for a {@link #visitParameterType} method call. */
	private static final EnumSet<State> VISIT_PARAMETER_TYPE_STATES =
	EnumSet.of(State.EMPTY, State.FORMAL, State.BOUND, State.PARAM);

	/** The valid automaton states for a {@link #visitReturnType} method call. */
	private static final EnumSet<State> VISIT_RETURN_TYPE_STATES =
	EnumSet.of(State.EMPTY, State.FORMAL, State.BOUND, State.PARAM);

	/** The valid automaton states for a {@link #visitExceptionType} method call. */
	private static final EnumSet<State> VISIT_EXCEPTION_TYPE_STATES = EnumSet.of(State.RETURN);

	/** The possible states of the automaton used to check the order of method calls. */
	private enum State {
	EMPTY,
	FORMAL,
	BOUND,
	SUPER,
	PARAM,
	RETURN,
	SIMPLE_TYPE,
	CLASS_TYPE,
	END;
	}

	private static final String INVALID = "Invalid ";

	/** The type of the visited signature. */
	private final int type;

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

	/** Whether the visited signature can be 'V'. */
	private boolean canBeVoid;

	/** The visitor to which this adapter must delegate calls. May be {@literal null}. */
	private final SignatureVisitor signatureVisitor;

	/**
	* Constructs a new {@link CheckSignatureAdapter}. <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 signatureVisitor the visitor to which this adapter must delegate calls. May be {@literal
	* null}.
	*/
	public CheckSignatureAdapter(final int type, final SignatureVisitor signatureVisitor) {
	this(/* latest api = */ Opcodes.ASM8, type, signatureVisitor);
	}

	/**
	* Constructs a new {@link CheckSignatureAdapter}.
	*
	* @param api the ASM API version implemented by this visitor. Must be one of {@link
	* Opcodes#ASM4}, {@link Opcodes#ASM5}, {@link Opcodes#ASM6}, {@link Opcodes#ASM7} or {@link
	* Opcodes#ASM8}.
	* @param type the type of signature to be checked. See {@link #CLASS_SIGNATURE}, {@link
	* #METHOD_SIGNATURE} and {@link #TYPE_SIGNATURE}.
	* @param signatureVisitor the visitor to which this adapter must delegate calls. May be {@literal
	* null}.
	*/
	protected CheckSignatureAdapter(
	final int api, final int type, final SignatureVisitor signatureVisitor) {
	super(api);
	this.type = type;
	this.state = State.EMPTY;
	this.signatureVisitor = signatureVisitor;
	}

	// class and method signatures

	@Override
	public void visitFormalTypeParameter(final String name) {
	if (type == TYPE_SIGNATURE \|\| !VISIT_FORMAL_TYPE_PARAMETER_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	checkIdentifier(name, "formal type parameter");
	state = State.FORMAL;
	if (signatureVisitor != null) {
	signatureVisitor.visitFormalTypeParameter(name);
	}
	}

	@Override
	public SignatureVisitor visitClassBound() {
	if (type == TYPE_SIGNATURE \|\| !VISIT_CLASS_BOUND_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	state = State.BOUND;
	return new CheckSignatureAdapter(
	TYPE_SIGNATURE, signatureVisitor == null ? null : signatureVisitor.visitClassBound());
	}

	@Override
	public SignatureVisitor visitInterfaceBound() {
	if (type == TYPE_SIGNATURE \|\| !VISIT_INTERFACE_BOUND_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	return new CheckSignatureAdapter(
	TYPE_SIGNATURE, signatureVisitor == null ? null : signatureVisitor.visitInterfaceBound());
	}

	// class signatures

	@Override
	public SignatureVisitor visitSuperclass() {
	if (type != CLASS_SIGNATURE \|\| !VISIT_SUPER_CLASS_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	state = State.SUPER;
	return new CheckSignatureAdapter(
	TYPE_SIGNATURE, signatureVisitor == null ? null : signatureVisitor.visitSuperclass());
	}

	@Override
	public SignatureVisitor visitInterface() {
	if (type != CLASS_SIGNATURE \|\| !VISIT_INTERFACE_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	return new CheckSignatureAdapter(
	TYPE_SIGNATURE, signatureVisitor == null ? null : signatureVisitor.visitInterface());
	}

	// method signatures

	@Override
	public SignatureVisitor visitParameterType() {
	if (type != METHOD_SIGNATURE \|\| !VISIT_PARAMETER_TYPE_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	state = State.PARAM;
	return new CheckSignatureAdapter(
	TYPE_SIGNATURE, signatureVisitor == null ? null : signatureVisitor.visitParameterType());
	}

	@Override
	public SignatureVisitor visitReturnType() {
	if (type != METHOD_SIGNATURE \|\| !VISIT_RETURN_TYPE_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	state = State.RETURN;
	CheckSignatureAdapter checkSignatureAdapter =
	new CheckSignatureAdapter(
	TYPE_SIGNATURE, signatureVisitor == null ? null : signatureVisitor.visitReturnType());
	checkSignatureAdapter.canBeVoid = true;
	return checkSignatureAdapter;
	}

	@Override
	public SignatureVisitor visitExceptionType() {
	if (type != METHOD_SIGNATURE \|\| !VISIT_EXCEPTION_TYPE_STATES.contains(state)) {
	throw new IllegalStateException();
	}
	return new CheckSignatureAdapter(
	TYPE_SIGNATURE, signatureVisitor == null ? null : signatureVisitor.visitExceptionType());
	}

	// type signatures

	@Override
	public void visitBaseType(final char descriptor) {
	if (type != TYPE_SIGNATURE \|\| state != State.EMPTY) {
	throw new IllegalStateException();
	}
	if (descriptor == 'V') {
	if (!canBeVoid) {
	throw new IllegalArgumentException("Base type descriptor can't be V");
	}
	} else {
	if ("ZCBSIFJD".indexOf(descriptor) == -1) {
	throw new IllegalArgumentException("Base type descriptor must be one of ZCBSIFJD");
	}
	}
	state = State.SIMPLE_TYPE;
	if (signatureVisitor != null) {
	signatureVisitor.visitBaseType(descriptor);
	}
	}

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

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

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

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

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

	@Override
	public SignatureVisitor visitTypeArgument(final char wildcard) {
	if (state != State.CLASS_TYPE) {
	throw new IllegalStateException();
	}
	if ("+-=".indexOf(wildcard) == -1) {
	throw new IllegalArgumentException("Wildcard must be one of +-=");
	}
	return new CheckSignatureAdapter(
	TYPE_SIGNATURE,
	signatureVisitor == null ? null : signatureVisitor.visitTypeArgument(wildcard));
	}

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

	private void checkClassName(final String name, final String message) {
	if (name == null \|\| name.length() == 0) {
	throw new IllegalArgumentException(INVALID + message + " (must not be null or empty)");
	}
	for (int i = 0; i < name.length(); ++i) {
	if (".;[<>:".indexOf(name.charAt(i)) != -1) {
	throw new IllegalArgumentException(
	INVALID + message + " (must not contain . ; [ < > or :): " + name);
	}
	}
	}

	private void checkIdentifier(final String name, final String message) {
	if (name == null \|\| name.length() == 0) {
	throw new IllegalArgumentException(INVALID + message + " (must not be null or empty)");
	}
	for (int i = 0; i < name.length(); ++i) {
	if (".;[/<>:".indexOf(name.charAt(i)) != -1) {
	throw new IllegalArgumentException(
	INVALID + message + " (must not contain . ; [ / < > or :): " + name);
	}
	}
	}
	}

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