src/java.base/share/classes/jdk/internal/classfile/attribute/StackMapFrameInfo.java - master - niceSOFT/openjdk21

src/java.base/share/classes/jdk/internal/classfile/attribute/StackMapFrameInfo.java
122 строки4 KB
Adam Sotona
8294982: Implementation of Classfile API
09 мар 2023, 18:23
09 мар 2023, 18:234655b79
/*
 * Copyright (c) 2023, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package jdk.internal.classfile.attribute;

import java.lang.constant.ClassDesc;
import java.util.List;

import jdk.internal.classfile.Label;
import jdk.internal.classfile.constantpool.ClassEntry;
import jdk.internal.classfile.impl.StackMapDecoder;
import jdk.internal.classfile.impl.TemporaryConstantPool;
import static jdk.internal.classfile.Classfile.*;

/**
 * Models stack map frame of {@code StackMapTable} attribute {@jvms 4.7.4}.
 */
public sealed interface StackMapFrameInfo
            permits StackMapDecoder.StackMapFrameImpl {

    int frameType();
    Label target();
    List<VerificationTypeInfo> locals();
    List<VerificationTypeInfo> stack();

    public static StackMapFrameInfo of(Label target,
            List<VerificationTypeInfo> locals,
            List<VerificationTypeInfo> stack) {

        return new StackMapDecoder.StackMapFrameImpl(255, target, locals, stack);
    }

    /**
     * The type of a stack value.
     */
    sealed interface VerificationTypeInfo {
        int tag();
    }

    /**
     * A simple stack value.
     */
    public enum SimpleVerificationTypeInfo implements VerificationTypeInfo {
        ITEM_TOP(VT_TOP),
        ITEM_INTEGER(VT_INTEGER),
        ITEM_FLOAT(VT_FLOAT),
        ITEM_DOUBLE(VT_DOUBLE),
        ITEM_LONG(VT_LONG),
        ITEM_NULL(VT_NULL),
        ITEM_UNINITIALIZED_THIS(VT_UNINITIALIZED_THIS);


        private final int tag;

        SimpleVerificationTypeInfo(int tag) {
            this.tag = tag;
        }

        @Override
        public int tag() {
            return tag;
        }
    }

    /**
     * A stack value for an object type.
     */
    sealed interface ObjectVerificationTypeInfo extends VerificationTypeInfo
            permits StackMapDecoder.ObjectVerificationTypeInfoImpl {

        public static ObjectVerificationTypeInfo of(ClassEntry className) {
            return new StackMapDecoder.ObjectVerificationTypeInfoImpl(className);
        }

        public static ObjectVerificationTypeInfo of(ClassDesc classDesc) {
            return of(TemporaryConstantPool.INSTANCE.classEntry(classDesc));
        }

        /**
         * {@return the class of the value}
         */
        ClassEntry className();

        default ClassDesc classSymbol() {
            return className().asSymbol();
        }
    }

    /**
     * An uninitialized stack value.
     */
    sealed interface UninitializedVerificationTypeInfo extends VerificationTypeInfo
            permits StackMapDecoder.UninitializedVerificationTypeInfoImpl {
        Label newTarget();

        public static UninitializedVerificationTypeInfo of(Label newTarget) {
            return new StackMapDecoder.UninitializedVerificationTypeInfoImpl(newTarget);
        }
    }
}