2025-01-08 03:37:28 +00:00

68 lines
2.7 KiB
Java

/*
* Copyright (c) 2022, 2025, 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 java.lang.classfile.constantpool;
import java.lang.classfile.CodeBuilder;
import java.lang.classfile.Opcode;
import java.lang.classfile.TypeKind;
import java.lang.classfile.instruction.ConstantInstruction;
import java.lang.constant.ConstantDesc;
/**
* Marker interface for constant pool entries suitable for loading via the
* {@link ConstantInstruction.LoadConstantInstruction ldc} instructions.
* <p>
* The use of a {@code LoadableConstantEntry} is modeled by a {@link ConstantDesc}.
* Conversions are through {@link ConstantPoolBuilder#loadableConstantEntry(ConstantDesc)}
* and {@link #constantValue()}.
*
* @see CodeBuilder#ldc(LoadableConstantEntry)
* @jvms 4.4 The Constant Pool
* @sealedGraph
* @since 24
*/
public sealed interface LoadableConstantEntry extends PoolEntry
permits ClassEntry, ConstantDynamicEntry, ConstantValueEntry, MethodHandleEntry, MethodTypeEntry {
/**
* {@return a symbolic descriptor of this constant}
*
* @see ConstantPoolBuilder#loadableConstantEntry(ConstantDesc)
*/
ConstantDesc constantValue();
/**
* {@return the data type of this constant}
* <p>
* If the data type is of {@linkplain TypeKind#slotSize() category} 2, this
* constant must be loaded with {@link Opcode#LDC2_W ldc2_w}; otherwise, the
* data type is of category 1, and this constant must be loaded with {@link
* Opcode#LDC ldc} or {@link Opcode#LDC_W ldc_w}.
*/
default TypeKind typeKind() {
return TypeKind.REFERENCE;
}
}