/*
 * 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
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 * This code is distributed in the hope that it will be useful, but WITHOUT
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/*
 * 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.HashSet;
import jdk.internal.org.objectweb.asm.ModuleVisitor;
import jdk.internal.org.objectweb.asm.Opcodes;

A ModuleVisitor that checks that its methods are properly used. 
Author:
Remi Forax/**
 * A {@link ModuleVisitor} that checks that its methods are properly used.
 *
 * @author Remi Forax
 */
public class CheckModuleAdapter extends ModuleVisitor {
    
Whether the visited module is open. /** Whether the visited module is open. */
    private final boolean isOpen;

    
The fully qualified names of the dependencies of the visited module. /** The fully qualified names of the dependencies of the visited module. */
    private final NameSet requiredModules = new NameSet("Modules requires");

    
The internal names of the packages exported by the visited module. /** The internal names of the packages exported by the visited module. */
    private final NameSet exportedPackages = new NameSet("Module exports");

    
The internal names of the packages opened by the visited module. /** The internal names of the packages opened by the visited module. */
    private final NameSet openedPackages = new NameSet("Module opens");

    
The internal names of the services used by the visited module. /** The internal names of the services used by the visited module. */
    private final NameSet usedServices = new NameSet("Module uses");

    
The internal names of the services provided by the visited module. /** The internal names of the services provided by the visited module. */
    private final NameSet providedServices = new NameSet("Module provides");

    
The class version number. /** The class version number. */
    int classVersion;

    
Whether the visitEnd method has been called. /** Whether the {@link #visitEnd} method has been called. */
    private boolean visitEndCalled;

    
Constructs a new CheckModuleAdapter. Subclasses must not use this constructor. Instead, they must use the CheckModuleAdapter(int, ModuleVisitor, boolean) version. 
Params:
moduleVisitor – the module visitor to which this adapter must delegate calls.
isOpen – whether the visited module is open. Open modules have their Opcodes.ACC_OPEN access flag set in ClassVisitor.visitModule.
Throws:
IllegalStateException – If a subclass calls this constructor./**
      * Constructs a new {@link CheckModuleAdapter}. <i>Subclasses must not use this constructor</i>.
      * Instead, they must use the {@link #CheckModuleAdapter(int, ModuleVisitor, boolean)} version.
      *
      * @param moduleVisitor the module visitor to which this adapter must delegate calls.
      * @param isOpen whether the visited module is open. Open modules have their {@link
      *     Opcodes#ACC_OPEN} access flag set in {@link jdk.internal.org.objectweb.asm.ClassVisitor#visitModule}.
      * @throws IllegalStateException If a subclass calls this constructor.
      */
    public CheckModuleAdapter(final ModuleVisitor moduleVisitor, final boolean isOpen) {
        this(/* latest api = */ Opcodes.ASM8, moduleVisitor, isOpen);
        if (getClass() != CheckModuleAdapter.class) {
            throw new IllegalStateException();
        }
    }

    
Constructs a new CheckModuleAdapter. 
Params:
api – the ASM API version implemented by this visitor. Must be one of Opcodes.ASM4, Opcodes.ASM5, Opcodes.ASM6, Opcodes.ASM7 or Opcodes.ASM8.
moduleVisitor – the module visitor to which this adapter must delegate calls.
isOpen – whether the visited module is open. Open modules have their Opcodes.ACC_OPEN access flag set in ClassVisitor.visitModule./**
      * Constructs a new {@link CheckModuleAdapter}.
      *
      * @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 moduleVisitor the module visitor to which this adapter must delegate calls.
      * @param isOpen whether the visited module is open. Open modules have their {@link
      *     Opcodes#ACC_OPEN} access flag set in {@link jdk.internal.org.objectweb.asm.ClassVisitor#visitModule}.
      */
    protected CheckModuleAdapter(
            final int api, final ModuleVisitor moduleVisitor, final boolean isOpen) {
        super(api, moduleVisitor);
        this.isOpen = isOpen;
    }

    @Override
    public void visitMainClass(final String mainClass) {
        // Modules can only appear in V9 or more classes.
        CheckMethodAdapter.checkInternalName(Opcodes.V9, mainClass, "module main class");
        super.visitMainClass(mainClass);
    }

    @Override
    public void visitPackage(final String packaze) {
        CheckMethodAdapter.checkInternalName(Opcodes.V9, packaze, "module package");
        super.visitPackage(packaze);
    }

    @Override
    public void visitRequire(final String module, final int access, final String version) {
        checkVisitEndNotCalled();
        CheckClassAdapter.checkFullyQualifiedName(Opcodes.V9, module, "required module");
        requiredModules.checkNameNotAlreadyDeclared(module);
        CheckClassAdapter.checkAccess(
                access,
                Opcodes.ACC_STATIC_PHASE
                        | Opcodes.ACC_TRANSITIVE
                        | Opcodes.ACC_SYNTHETIC
                        | Opcodes.ACC_MANDATED);
        if (classVersion >= Opcodes.V10
                && module.equals("java.base")
                && (access & (Opcodes.ACC_STATIC_PHASE | Opcodes.ACC_TRANSITIVE)) != 0) {
            throw new IllegalArgumentException(
                    "Invalid access flags: "
                            + access
                            + " java.base can not be declared ACC_TRANSITIVE or ACC_STATIC_PHASE");
        }
        super.visitRequire(module, access, version);
    }

    @Override
    public void visitExport(final String packaze, final int access, final String... modules) {
        checkVisitEndNotCalled();
        CheckMethodAdapter.checkInternalName(Opcodes.V9, packaze, "package name");
        exportedPackages.checkNameNotAlreadyDeclared(packaze);
        CheckClassAdapter.checkAccess(access, Opcodes.ACC_SYNTHETIC | Opcodes.ACC_MANDATED);
        if (modules != null) {
            for (String module : modules) {
                CheckClassAdapter.checkFullyQualifiedName(Opcodes.V9, module, "module export to");
            }
        }
        super.visitExport(packaze, access, modules);
    }

    @Override
    public void visitOpen(final String packaze, final int access, final String... modules) {
        checkVisitEndNotCalled();
        if (isOpen) {
            throw new UnsupportedOperationException("An open module can not use open directive");
        }
        CheckMethodAdapter.checkInternalName(Opcodes.V9, packaze, "package name");
        openedPackages.checkNameNotAlreadyDeclared(packaze);
        CheckClassAdapter.checkAccess(access, Opcodes.ACC_SYNTHETIC | Opcodes.ACC_MANDATED);
        if (modules != null) {
            for (String module : modules) {
                CheckClassAdapter.checkFullyQualifiedName(Opcodes.V9, module, "module open to");
            }
        }
        super.visitOpen(packaze, access, modules);
    }

    @Override
    public void visitUse(final String service) {
        checkVisitEndNotCalled();
        CheckMethodAdapter.checkInternalName(Opcodes.V9, service, "service");
        usedServices.checkNameNotAlreadyDeclared(service);
        super.visitUse(service);
    }

    @Override
    public void visitProvide(final String service, final String... providers) {
        checkVisitEndNotCalled();
        CheckMethodAdapter.checkInternalName(Opcodes.V9, service, "service");
        providedServices.checkNameNotAlreadyDeclared(service);
        if (providers == null || providers.length == 0) {
            throw new IllegalArgumentException("Providers cannot be null or empty");
        }
        for (String provider : providers) {
            CheckMethodAdapter.checkInternalName(Opcodes.V9, provider, "provider");
        }
        super.visitProvide(service, providers);
    }

    @Override
    public void visitEnd() {
        checkVisitEndNotCalled();
        visitEndCalled = true;
        super.visitEnd();
    }

    private void checkVisitEndNotCalled() {
        if (visitEndCalled) {
            throw new IllegalStateException("Cannot call a visit method after visitEnd has been called");
        }
    }

    private static class NameSet {

        private final String type;
        private final HashSet<String> names;

        NameSet(final String type) {
            this.type = type;
            this.names = new HashSet<>();
        }

        void checkNameNotAlreadyDeclared(final String name) {
            if (!names.add(name)) {
                throw new IllegalArgumentException(type + " '" + name + "' already declared");
            }
        }
    }
}